The First Topic: Definition of Currency Exchange Linguistically and its Islamic (Shari'a) meaning:
Currency exchange (al-sarf) linguistically refers to turning something away from its original course. One says "sarafahu yasrifuhu sarfan" (he turned it away), and it can have several meanings, including: trickery, increase, and excess. For example, one says, "I exchanged dirhams for dinars," and it is said, "There is  a sarf  between the two dirhams," meaning there is excess due to the higher quality of one’s silver. Also, one says, "I exchanged gold for dirhams," meaning, "I sold it." The active noun (doer of the action) from this is "sarraf " or "sarif," meaning money changer [362] - See: "Mukhtar Al-Sihah" (p. 175); "Lisan Al-Arab" (9/189); "Al-Misbah Al-Munir" (1/338). .
In Islamic jurisprudence (fiqh), currency exchange refers to the selling of money for money, whether the currencies are of the same type or different [363] - See: "Al-Mabsut "(14/2); "Hashiyat Ibn Abidin" (5/172). .
In economics, currency exchange refers to the exchange of national currency for foreign currency, and it also refers to the exchange rate [364] -See: "Al-Mu'jam Al-Wasith" (1/513). .
The Second Topic: The Ruling on Currency Exchange
Currency exchange is permissible if its conditions are met, and this is agreed upon by the four major schools of Islamic jurisprudence [365] -Al-Qurtubi said: "The compensation among the Arabs varies according to what is being exchanged. If one of the exchanged items is in exchange for a property, it is called a sale. If it is in exchange for the benefit of a property, and if the benefit is sexual intercourse, it is called marriage; if the benefit is something else, it is called rental. If it is an item for an item, it is the sale of cash, which is also known as 'sarf.' If it is in exchange for a deferred debt, it is known as 'salam.'"    "Al-Tafsir Al-Qurtubi" (3/357). : Hanafi [366] -"Mukhtasar Al-Quduri" (p. 90); "Al-‘Inayah" by Al-Babarti (7/133). , Maliki [367] -"Sharh Al-Zurqani 'ala Mukhtasar Khalil" (5/4); "Minhaj Al-Jalil" by 'Ulayish (4/433). , Shafi'i [368] - "Al-Majmu' " by Al-Nawawi (9/403); "Mughni al-Muhtaj "by Al-Shirbini (2/43). , and Hanbali [369] - "Kashaf al-Qina' "by Al-Buhuti (3/266); "Sharh Muntaha Al-Iradat" by Al-Buhuti (2/73). .
The Evidences:
Firstly: From the Sunnah:
(1) On the authority of Malik ibn Aws  رضي الله عنه: "He sought an exchange for one hundred dinars, so Talha ibn Ubayd Allah invited me, and we bargained until he exchanged it with me. He then took the gold, turning it over in his hand, and said, 'Wait until my treasurer comes from the forest.' 'Umar heard this and said, 'By Allah, do not leave him until you take it from him,' for the Messenger of Allah صلى الله عليه وسلم said: 'Gold for gold is Riba (interest or Usury), except if it is hand to hand (immediate); wheat for wheat is Riba, except hand to hand; barley for barley is Riba, except hand to hand; dates for dates is Riba, except hand to hand. [370] -It was narrated by Al-Bukhari (2174) with this wording, and by Muslim (1586). '"
Reasoning:
The Prophet صلى الله عليه وسلم allowed currency exchange if the items being exchanged are of different kinds with a difference in value, provided it is done hand to hand (immediately). However, if the items are of the same kind, equality and hand-to-hand exchange are required [371] -" Al-Majmu' '"by Al-Nawawi (9/403). .
(2) On the authority of Sulayman ibn Abi Muslim, who said: "I asked Abu Al-Minhāl about currency exchange hand to hand, and he said: 'My partner and I bought something hand to hand and on credit. Then Al-Bara’ ibn Azib came to us, so we asked him, and he said: 'My partner Zaid ibn Arqam and I did the same and asked the Prophet صلى الله عليه وسلم about it, and he said: 'What is hand to hand, take it; and what is on credit, leave it. [372] -This narration has been reported by al-Bukhari (2497- 2498), and the wording is his, and by Muslim (1589). ''
Reasoning:
The Prophet صلى الله عليه وسلم permitted currency exchange provided it is not deferred (on credit) [373] -See: Sharḥ Ṣaḥīḥ al-Bukhārī by Ibn Baṭṭāl (5/135). .
Secondly :From the Athar (sayings of the Companions and their students):
On the authority of Abu Nadhrah, who said: "I asked Ibn 'Abbas about currency exchange, and he said: 'Is it hand to hand?' I said: 'Yes.' He said: 'Then there is no problem with it. [374] -Narrated by Muslim,(1594) '"
The Third Topic: Conditions for the Sale of Currency Exchange
The First branch: Equality When the Type is the Same  ###
It is required in currency exchange (al-sarf الصرف  ) that there be equality when the type (of currency) is the same, and this is agreed upon by the four schools of Islamic jurisprudence: Hanafi [375] -See: "al-Hidāyah" by al-Marghīnānī (3/62); "Ḥāshiyat al-Shilbī ʿalā Tabīyn al-Ḥaqāʾiq" by al-Zaylaʿī (4/85). , Maliki [376] -There is a concession for a small increase when selling by count under specific conditions; the situation can be one of two cases: First case: If gold is sold for gold by weight, equality in weight is obligatory, even if there is a difference in number, and any increase is not permissible, even if it is done out of goodwill and leniency. Second case: If gold is sold for gold by count, a small increase is allowed out of goodwill and leniency under the following conditions: The exchange must occur using the term "exchange" (mubādalah), The items must be counted, The number must be small, less than seven, The increase must be in weight, not in number, For every dinar or dirham, the increase should be no more than one-sixth, The transaction should be intended as an act of goodwill. See: "al-Tāj wa al-Iklīl" by al-Mawwāq (4/300-301); "Mawāhib al-Jalīl" by al-Ḥaṭṭāb (6/125, 175); "Ḥāshiyat al-Dusūqī ʿalā al-Sharḥ al-Kabīr" (3/41); "Minḥat al-Jalīl" by ʿUlaysh (4/521, 525). , Shafi'i [377] - See: "Fatḥ al-ʿAzīz "by al-Rāfiʿī (8/165); "Rawḍat al-Ṭālibīn" by al-Nawawī (3/380) , and Hanbali [378] - See: "Kashshāf al-Qināʿ "by al-Buhūtī (3/251); "Maṭālib Uwlī al-Nuhā" by al-Ruḥaybānī (3/157). , and consensus (ijma') has been reported on this [379]-Ibn Rushd said: "The scholars are unanimous that neither excess (tafāḍul) nor delay (nasa') is permissible in the same category of commodities mentioned in the ḥadīth of ʿUbādah ibn al-Ṣāmit, except what has been reported from Ibn ʿAbbās. The Hadīth of ʿUbādah is: 'I heard the Messenger of Allah, peace and blessings be upon him, forbidding the sale of gold for gold, silver for silver, wheat for wheat, barley for barley, dates for dates, and salt for salt, except equal for equal, hand to hand. Whoever gives more or takes more has engaged in usury (riba).' This ḥadīth explicitly prohibits excess in the same category of these items."  See: Bidāyat al-Mujtahid by Ibn Rushd (3/148). Ibn Qudāmah said: "Chapter: Usury (riba) is of two types: : riba al-faḍl and riba al-nasīʾah  The scholars are unanimous in prohibiting both." See: "al-Mughnī" by Ibn Qudāmah (4/3). He also said: "These commodities explicitly mentioned are subject to riba according to the text and the consensus of the scholars. The scholars have differed regarding other commodities." See: "al-Mughnī" by Ibn Qudāmah (4/4). He further stated: "The scholars agree that riba al-faḍl applies only within the same category, except for Saʿīd ibn Jubayr, who said: Any two items that have similar benefits cannot be sold one for the other with a difference in quantity, such as wheat for barley, dates for raisins, and millet for sorghum, because their benefits are similar, and they thus take the same ruling as two types of the same category."  See: "al-Mughnī" by Ibn Qudāmah (4/4). .
The Evidence from the Sunnah:
1. On the authority of Abu Sa'id al-Khudri رضي الله عنه the Messenger of Almighty Allah صلى الله عليه وسلم said: “Do not sell gold for gold except like for like, and do not increase one over the other. Do not sell silver for silver except like for like, and do not increase one over the other, and do not sell something that is absent for something that is present. [380] -It was narrated by al-Bukhārī (2177) and Muslim (1584). ”
Reasoning:
The Prophet صلى الله عليه وسلم forbade any disparity in the exchange of the same kind of item with his saying: “do not increase one over the other. [381] -See: "Sharh Muslim" by al-Nawawi (11/10); "Umdat al-Qari" by al-Ayni (11/294, 295). ”
2. On the authority of Abu Hurairah (رضي الله عنه), the Messenger of Almighty Allah (صلى الله عليه وسلم) said: “Gold for gold, weight for weight, like for like, and silver for silver, weight for weight, like for like. Whoever adds or asks for more has committed Riba (usury). [382] -Narrated by Muslim (1588). ”
Reasoning:
The Prophet صلى الله عليه وسلم  ordered that the weight be equal when selling gold for gold and silver for silver, and he informed us that any disparity in the same type constitutes Riba (usury) [383] -See:" Ihkam al-Ahkam" by Ibn Daqiq al-Eid (2/142). .
3. On the authority of Abd al-Rahman ibn Abi Bakra, Abu Bakra رضي الله عنه said: The Messenger of Allah صلى الله عليه وسلم said: “Do not sell gold for gold except like for like, and silver for silver except like for like. Sell gold for silver, and silver for gold, however you wish. [384] - Reported by Al-Bukhari (2175) and the wording is his, and Muslim (1590). ”
Reasoning:
The Prophet صلى الله عليه وسلم forbade selling gold for gold and silver for silver with a disparity, and he ordered equality between them [385] -See: Sharh Sahih Al-Bukhari by Ibn Battal (6/300) .
4. On the authority of Uthman ibn Affan  رضي الله عنه the Messenger of Almighty Allah صلى الله عليه وسلم said: “Do not sell one dinar for two dinars, nor one dirham for two dirhams. [386] -Narrated by Muslim (1585) ”
Reasoning:
The Prophet صلى الله عليه وسلم forbade any disparity when the type is the same, such as gold for gold (one dinar for one dinar) and silver for silver (one dirham for one dirham) [387] -See: "Sharh Al-Zurqani on Al-Muwatta" (3/419) .
The Second Branch: Selling currency for currency with one or both of them an addition of an item from a different type.
The Jurisprudents had different opinions regarding the ruling on selling currency for currency, with one or both of them having something of a different type [388] - Ibn Taymiyyah said: “The sale of the dirhams of silver, which consist of approximately two-thirds of silver, for black dirhams, which consist of approximately one-fourth, or less or more, pertains to the issue of ‘a mudd of dates.’ The essence of it is selling a Ribawi (usury-based) item with something else of the same ribawi type. The people are divided between two extremes of prohibition and permissibility, and in between them are intermediaries. If the objective is to sell the ribawi item with its same type in a different quantity, and the other is introduced as a ruse—like someone selling two thousand dirhams for one thousand dirhams in a handkerchief or two qafiz of wheat for one qafiz in a basket—this is undoubtedly prohibited, as held by the schools of Malik, Al-Shafi’i, and Ahmad. If the objective is permissible sales, and involving a ribawi item is secondary—like selling sheep for sheep when both have milk and wool, or selling sheep with milk for milk, or selling a house decorated with gold, or selling silver jewelry with gold, with a small amount of gold adorning it—this is correct and permitted, as is the well-known view of Ahmad and others. As for both types being intended, there is a well-known dispute over them. Some prohibited it, while others permitted it, like the view of Abu Hanifah and others. The other narration from Ahmad states: If the singular item exceeds what is accompanied by another... As for the sale of the silver dirhams for black ones, if the intention is not to exchange silver for silver in different quantities, then the copper in the black ones is the target, and it is a connection between the silver (dirhams) and the coins. This is addressed in the well-known dispute regarding ‘a mudd of dates,’ as silver and copper are sold for silver and copper, which are intended, and the more similar outcome is permissibility in that.” "Majmu' al-Fatawa" (29/464).   added; there are two opinions:
The First Opinion: It is not permissible to sell currency for currency of the same type, with one or both of them having something of a different type added.
The Second Opinion: It is permissible to sell currency along with something else for currency of the same type, provided that the price (i.e., the standalone currency) exceeds the attached currency.
The Second Issue: Mutual possession (at-taqabud, التقابض) even if the types differ.
The First Branch: The requirement of mutual possession even if the types differ
Mutual possession (at-taqabud, التقابض) is required in currency exchange, even if the types differ.
The Evidences:
Firstly: From the Sunnah
1. On the authority of Abu al-Minhāl رضي الله عنه, he said: “I asked al-Bara' ibn 'Azib and Zaid ibn Arqam رضي الله عنهما about currency exchange. They said: We were merchants during the time of the Messenger of Allah صلى الله عليه وسلم  and we asked the Messenger of Allah صلى الله عليه وسلم about currency exchange. He said: ‘If it is hand to hand, it is permissible, but if there is delay, it is not valid. [389] -It was narrated by Al-Bukhari (2060, 2061) with the wording attributed to him, and by Muslim (1589). ’”
Reasoning:
He stipulated mutual possession absolutely, whether the types are the same or different [390] -See: "Umda al-Qari" by Al-Ayni (11/175); "Irshad al-Sari" (4/13). .
2. On the authority of 'Ubadah ibn al-Samit رضي الله عنه the Messenger of Almighty Allah صلى الله عليه وسلم said: “Gold for gold, silver for silver, wheat for wheat, barley for barley, dates for dates, and salt for salt, like for like, equal for equal, hand to hand. But if these types differ, then sell as you wish, provided it is hand to hand [391] - Narrated by Muslim (1587). .”
Reasoning:
He stipulated mutual possession when the types are the same with his saying: “hand to hand,” and when the types differ with his saying: “provided it is hand to hand. [392] - See: "Fath al-Bari" by Ibn Hajar (4/383). ”
Secondly: From the Consensus (Ijma')
Consensus on this has been transmitted by Ibn al-Mundhir [393] -Ibn al-Mundhir said: “All those from whom we have preserved knowledge among the scholars have unanimously agreed that if the two parties engaged in a transaction part ways before they exchange (the goods), then the transaction is invalid.” "Al-Awsat" (10/197) , Ibn 'Abd al-Barr [394] -Ibn Abd al-Bar said: “The consensus among scholars has been established that usury involves an increase in gold for gold and in silver for silver, just as it does in deferred transactions. This applies equally to the sale of one for the other and to the sale of parts of each for parts of the other. This is a matter of consensus, with no disagreement among the scholars, supported by numerous reports from the Prophet (peace be upon him) on this issue.” "Al-Tamhid" (6/287). , Ibn Rushd [395] -Ibn Rushd said: “The scholars have agreed that one of the conditions of currency exchange (sarf) is that it must take place instantly.” "Bidayat al-Mujtahid" (3/213). , Ibn Qudamah [396] -Ibn Qudamah said: “The sale of currencies among themselves, and the immediate possession in the session is a condition for its validity without dispute.” "Al-Mughni" (4/41). , al-Nawawi [397] -An-Nawawi said: “The scholars unanimously agree on the prohibition of selling gold for gold, or for silver on credit, as well as wheat for wheat, or for barley, and likewise for any two items that share the same reason for usury.” "Sharh Sahih Muslim" (11/10). , and Ibn Taymiyyah [398] -Ibn Taymiyyah said: “The prohibition of nas' (postponement) is unanimously agreed upon by the ummah." "Majmu' al-Fatawa" (29/470). .
The Second Branch: Delayed possession (Laxity in receipt)
Immediate possession is not required. Possession is valid even if the session is prolonged, as long as they do not part physically. This is the view of the majority: the Hanafi [399] -"Al-Hidayah" by al-Marghinani (3/63); "Al-Fatawa al-Hindiya" (3/217) , Shafi'i [400] -"Rawdat al-Talibin" by al-Nawawi (4/3); and see: "Al-Bayan" by al-Imrani (5/175). , and Hanbali [401] -"Al-Insaf" by Al-Mardawi (4/263); "Kashaf Al-Qina" by Al-Buhuti (3/266) schools.
Evidence from the Athar (Saying of the companions and their students)
1. On the authority of Malik ibn Aws رضي الله عنه: “He sought exchange for one hundred dinars, and Talha ibn 'Ubaydullah called me. We bargained until he exchanged with me. He took the gold, turning it over in his hand, then said: 'Until my treasurer comes from the forest.' 'Umar رضي الله عنه   heard this and said: 'By Allah, you will not leave him until you take from him.' The Messenger of Allah صلى الله عليه وسلم said: 'Gold for gold is Riba unless it is hand to hand, wheat for wheat is Riba unless it is hand to hand, barley for barley is Riba unless it is hand to hand, and dates for dates are Riba unless it is hand to hand. [402] -Narrated by Bukhari (2174) and the wording is his and Muslim(1586) ’”
2. On the authority of 'Abdullah ibn 'Umar رضي الله عنهما: “'Umar ibn al-Khattab said: 'Do not sell gold for gold unless it is like for like, and do not increase one over the other. Do not sell silver for silver unless it is like for like, and do not increase one over the other. Do not sell gold for silver, one of them absent, and the other immediate. If he asks you to wait until he enters his house, do not wait; I fear for you Usury (Riba). [403] - It was narrated by Mālik (2/634), and the wording is his, and by al-Ṭaḥāwī in "Sharḥ Ma‘ānī al-Āthā"r (5783), and by al-Bayhaqī (10796) in a summarized form. It was authenticated by Ibn Ḥazm in "al-Muḥallā" (8/504) '”
Reasoning:
When 'Umar رضي الله عنه said: “By Allah, you will not leave him Narratednot wait,” while citing the saying of the Prophet صلى الله عليه وسلم: “Gold for gold is Riba unless it is hand to hand,” it indicates that the intended meaning is possession before parting from the session, without requiring immediate possession [404] -See: "al-Tamhīd" by Ibn ʿAbd al-Barr (6/290). .
The Third Branch: Possession in currency exchange.
The basic principle in currency exchange is that it should occur through hand-to-hand transfer [405] -Receipt may be considered constructive in the following cases: 1.      When an amount of money is deposited directly into the client’s account or through a bank transfer. 2.      When the client enters into an immediate currency exchange contract with the bank, whereby one currency is exchanged for another in the client’s account. 3.      When the bank, at the client's order, transfers an amount from one account to another in a different currency, whether within the same bank or another, either for the client’s benefit or for the benefit of another. A delay in the bank entry is excused, provided the beneficiary is able to take actual possession within the customary timeframes in the trading markets. 4.      The receipt of a check, provided it has sufficient funds that can be withdrawn in the currency stated on the check. See: Resolution of  Islamic Fiqh Council, (No. 55/4/6), regarding the forms of receipt, held during its sixth session in Jeddah, Saudi Arabia in 1410 AH, corresponding to 1990 CE. Also see: In This Book, Topic on the receipt of commercial papers (1/418).   , and this is agreed upon by the four major Islamic jurisprudential schools: Hanafi [406] -"Tabyīn al-Ḥaqāʾiq" by al-Zaylaʿī (4/138); ”al-Baḥr al-Rāʾiq" by Ibn Nujaym (6/210); "Ḥāshiyat Ibn ʿĀbidīn" (5/258); "al-Fatāwā al-Hindiyya" (3/217) , Maliki [407] -"al-Kāfī" by Ibn ʿAbd al-Barr (2/635); "al-Tāj wa al-Iklīl" by al-Mawwāq (4/302); "Mawāhib al-Jalīl" by al-Ḥaṭṭāb (6/129); "al-Fawākih al-Dawānī" by al-Nafrawī (2/74). , Shafi'i [408] -"Rawḍat al-Ṭālibīn" by al-Nawawī (3/523); "al-Majmūʿ" by al-Nawawī (9/276). , and Hanbali [409] -"al-Furūʿ" by Ibn Mufliḥ (6/284). .
The Evidences:
Firstly: From the Sunnah
1. From Abu Sa'id al-Khudri رضي الله عنه who reported that the Messenger of Allah صلى الله عليه وسلم  said: "Gold for gold, silver for silver, wheat for wheat, barley for barley, dates for dates, and salt for salt, in equal measure, hand to hand; whoever increases or requests more has engaged in usury, and both the giver and receiver are equally culpable in this. [410] - Narrated by Muslim (1584) "
2. From Ubadah ibn al-Samit رضي الله عنه who reported that the Messenger of Allah صلى الله عليه وسلم said: "Gold for gold, silver for silver, wheat for wheat, barley for barley, dates for dates, and salt for salt, in equal measure, equal for equal, hand to hand. If these types differ, sell as you wish, provided it is hand to hand. [411] -Narrated by Muslim (1587) "
Reasoning:
His statement "hand to hand" clarifies the limit of delivery and receipt, as the hand is the means of taking possession of items that can be possessed [412] -See: "Asnā al-Maṭālib" by Zakariyyā al-Anṣārī (2/22); "Ghayat al-Bayān Sharḥ Zubad Ibn Raslān" by al-Ramlī (p. 184). .
Secondly: Because the exchanged currencies are subject to hand-to-hand transfer, and taking possession of items involves using the hand [413] -See: "al-Furūʿ" by Ibn Mufliḥ (6/284). .
The Fourth Branch: The Acceptance of Certified Checks as a Substitute for Taking Possession of Currency Exchange.
The acceptance of certified checks serves as a substitute for taking possession of currency exchange [414] -See the section on: Receipt of Commercial Papers. .
The Fifth Branch: Disposal of the currency's price Before Possession (receipt)
It is not permissible to dispose of the currency's price [415] -It is as if a person exchanges one hundred riyals for thirty dollars from another. Before he receives the thirty dollars, he engages in transactions with them; such as giving them as a gift, paying zakah, or using them to make a purchase. before taking possession of it.