Overall Meaning: Meaning of trustworthiness:
Amanah linguistically: Amn, amanah, and aman are all original roots. Aman is sometimes used to mean the state one is in when safe, and sometimes for what one is entrusted with. An example of the latter is His saying, sanctified, “Betraying your amanat (trusts).” 
(al-Anfal: 27) Meaning, those things you were entrusted upon. Another example is His saying, “Indeed, We offered the trust for the heavens and the earth.”
(al-Ahzab: 72) [34] al-Mufradat, al-Raghib (1/133).
Amanah technically: It is every right that one must adhere to and preserve. [35] Fayd al-Qadir, al-Manawi (1/288). Everything obligatory upon the slaves of Allah is a trust, like prayer, legal charity, fasting, and repaying debts. The most stressed among debts are consignments, and the most stressed among consignments is concealing secrets. [36] al-Kulliyyat, al-Kafawi (p. 269).

Encouragement towards returning trusts from the Qur’an and the Sunnah:
❖ Allah, exalted, says, “Indeed, Allah commands you to return trusts to their rightful owners; and when you judge between people, judge with fairness. What a noble commandment from Allah to you! Surely Allah is All-Hearing, All-Seeing.” (al-Nisa’: 58)
❖ Allah, exalted, says regarding the characteristics of the successful ones, “Those who are true to their trusts and covenants.” (al-Mu’minun: 8)
❖ Abu Hurayrah, Allah be pleased with him, said that the Prophet ﷺ said, “The signs of the hypocrite are three: when he speaks, he lies; when he promises, he breaks his promise; and when he is entrusted, he betrays the trust.” [37] Reported by al-Bukhari (33) and Muslim (59).

Quotes from the predecessors and scholars on trustworthiness:
❖ `Umar, Allah be pleased with him, is reported to have said, “It does not beguile me the prayer of a man, nor his fasting. Whoever wishes can fast and pray. There is no religiosity for the one who is not trustworthy.” [38] Reported by al-Khallal in al-Sunnah (1491), and al-Khara’iti in Makarim al-Akhlaq (162), and the wording is his.
❖ Sufyan ibn `Uyaynah is reported to have said, “Whoever has no capital, let him take trustworthiness as his capital.” [39] Reported by al-Bayhaqi in Shu`ab al-Iman (5284).
❖ Khalid al-Raba`i said, “It used to be said, ‘Indeed, among those acts most worthy of not having their punishment delayed - or it should be hastened -: that a trust be betrayed, ties of kinship be severed, and kindness belied.’” [40] Reported by al-Khara’iti in Makarim al-Akhlaq (168).

Benefits of trustworthiness: [41] Nadrat al-Na`im, authored by a number of researchers (3/524).
1- Trustworthiness is from perfect faith and good Islam. Upon it, the matters of the heavens and the earth are fulfilled. 
2- Through trustworthiness, religion is preserved. Likewise chastity and honour, wealth, physical well-being, spiritual well-being, knowledge, and science. Also guardianship, testaments, testification, adjudication, and dictation (in will-writing, contracts, and so on). 
3- The trustworthy one is loved by Allah and the people. 
4- A society where trustworthiness is widespread is one that is good and blessed. 

Among the forms of trustworthiness: [42] Bustan al-`Arifin, al-Nawawi (p. 15), Sharh Riyad al-Salihin, Ibn `Uthaymin (2/462), al-Akhlaq al-Islamiyyah, `Abd al-Rahman al-Maydani (1/595).
1- Trustworthiness in what Allah has obligated upon His slaves which He has made them accountable for. 
2- Trustworthiness in wealth. This is realised when a person desists from wealth in which he has no right whilst spending what he must upon his kin, and fulfilling their financial rights from the wealth he owns. 
3- Trustworthiness in not delving in others’ honour. This is realised through desisting from that which one has no right in, withholding one’s tongue from uttering evil regarding another, like backbiting and slander. 
4- Trustworthiness in preserving body and soul. This is realised by not allowing oneself to be a source of physical harm - not killing, wounding, injuring, or harming others. 

Trustworthiness in academia:
It is sound practise when it comes to advice that an unknown benefit be attributed to its author. Whoever does this will be blessed in his knowledge and overall state. Whoever does not, and pretends that another’s contribution is his, then he is deserving of his knowledge not being benefited from, and that he does not find blessings in his endeavours. True scholars and those of virtue always attribute a benefit to he who authored it. 

Trustworthiness in governance:
This is realised by fulfilling others’ rights, and allowing the rightful, qualified, and able, to have access to their respective prerogatives. It is also preserving the people’s wealth, bodies, souls, and minds, as well as preserving the religion which Allah has ordained for His slaves, that no one harms it. Furthermore, protecting the state’s secrets, not allowing its enemies to have access to that which they can use to harm it. All this, as well as other matters of sound, trusted governance. Trustworthiness in testification. This is realised by bearing testimony in accordance to what is actually witnessed in reality, delivering it without alteration, increase, or decrease.

Trustworthiness in adjudication:
This is realised by giving just verdicts, which the judge has been entrusted with when the matter was commissioned to him. Trustworthiness in writing. This is realised when what is written is in accordance with that which is dictated, or in accordance with the original source from which a copy is being made. This, without alteration, increase, or decrease. If it is a novel document as opposed to a copy, then its content must be free from lies, fraud, and their like. Trustworthiness in keeping secrets one has been entrusted with by not making it known to others. 

Examples of trustworthiness from the life of the Prophet ﷺ and past nations:
❖ The most popular of those accredited with trustworthiness is our prophet Muhammad ﷺ, and this throughout his life, before his prophethood and after it. He was known among his people before prophethood as ‘the trustworthy.’ It was the reason why his marriage with Khadijah, Allah be pleased with her, took place. He ﷺ used to do business with her wealth before prophethood. He was described as being truthful in his speech and trustworthy in his dealings. Ibn al-Athir says in this regard, “When it reached her - meaning Khadijah - that Allah’s Messenger ﷺ was truthful in his speech, trustworthy in his dealings, and noble in character, she sent to him that he is to go to the Levant to do business with her wealth there, and that she will give him the best she gives her business partners with her servant Maysarah. He ﷺ accepted, and went forth to the Levant with Maysarah.” [43] al-Sirat al-Nabawiyyah, Ibn Hisham (1/139); al-Kamil, Ibn al-Athir (2/26). When he returned to Makkah and Maysarah narrated to Khadijah the affairs of Muhammad ﷺ, she decided to marry him. After his prophethood, Allah’s Messenger ﷺ fulfilled the greatest trust he was entrusted with - messengerhood - to an immaculate degree, and he bore the greatest of burdens and suffering in its cause.
❖ Abu Hurayrah, Allah be pleased with him, said, “The Messenger of Allah ﷺ said, ‘A man bought some land from another, and the buyer found a box filled with gold therein. He said to the one from whom he bought the property, “Take your gold from me, for I only bought the land from you.” The seller replied, “I sold you the land with whatever is in it.” They then sought judgement from a third man. He said, “Do you have children?” One of them said, “I have a boy.” The other said, “I have a girl.” The man judging between them said, “Marry the girl to the boy, spend from the gold upon yourselves, and give in charity.”’” [44] Reported by al-Bukhari (3472) and Muslim (1721), and the wording is his.

Trustworthiness in poetry:
Ali ibn Abi Talib, Allah be pleased with him, said,
“Fulfil your trusts and return them. Avoid betrayal.
Be just and do not oppress - your gain will be pure.” [45] Diwan `Ali ibn Abi Talib (p. 58).