The First Topic: Definition of the Sale of "Muzabana" Linguistically and its Islamic (Shari'a) meaning:
· Linguistic Definition of "Muzabana": Muzabana refers to mutual pushing or exchange, derived from the root zabn, meaning pushing [304] -See: "Tahthib al-Lughah" by Al-Azhari (13/155); "Maqayis al-Lughah" by Ibn Faris (3/46).     Al-'Ayni said: "This type of sale is named as such because it leads to disputes and conflict, as it is based on estimation, and deception in it is common. The one who is deceived wants to negate it, while the deceiver wants to enforce it; thus, they push against each other." See: "al-Binayah" (8/152). .
· Islamic (Shari'a)  Definition of "Muzabana": It refers to selling unharvested dates on palm trees for a measured amount of harvested dates, estimated by volume [305]- See: "Al-Bahr Al-Raiq" by Ibn Nujaym (6/82). Kharsan: meaning estimation and approximation. Ibn Abd Al-Barr defined Al-Muzabana in a way that indicates it encompasses dates and others; he said: "Al-Muzabana means selling any known item for an unknown item of its kind among all consumables and beverages, as well as selling all fresh produce for dry. The interpretation of this is that selling fresh dates for dry dates is not permitted in any case, neither equally nor unequally, nor selling wheat for dates or fresh produce in any condition, nor selling crops for wheat in any condition, nor selling raisins for grapes in any condition, nor is it permissible to sell dried figs for fresh figs in any condition, nor to sell freekeh for wheat in any condition, nor wet wheat for dry wheat, nor wet for wet unless the moisture is identical in one type of wheat. It is also not permissible to sell flour for dough in any situation, and likewise for all similar items." See: "Al-Kafi "(2/652). He said: "Malik explained Al-Muzabana in Al-Muwatta with an interpretation agreed upon by scholars, while some points are debated; he said: 'The interpretation of Al-Muzabana is that any item sold based on estimation, whose measurement, weight, or number is unknown, is exchanged for a specified item by measurement, weight, or number.' Abu Umar said: This statement is correct according to the majority of scholars if it pertains to consumables or beverages that are measured or weighed, or it is gold or silver. As for other matters, there are differing opinions on each item within its chapter and place - if Allah wills. However, the foundation of Malik’s opinion regarding items other than consumables is that Al-Muzabana does not apply unless it pertains to gambling, risk, and uncertainty, allowing Al-Muzabana  where superiority is permitted and where it is not if the intention leads to the aforementioned uncertainty, gambling, and risk." As for Al-Shafi'i, may Allah have mercy on him, he said: "The essence of Al-Muzabana is that all sales involving a superiority of one over the other should be examined; nothing is allowed to be exchanged for something known in measurement or weight against something estimated, nor can estimations be exchanged for estimations of the same type; rather, if he says to you: 'I guarantee you this bushel for twenty sa's, whatever exceeds that is mine, and whatever is less than that is my responsibility,' this is considered gambling and risk, not Al-Muzabana ." See: "Al-Istidhkar" (6/334-335).  
Second Topic: The Ruling on the Sale of Muzabana
The sale of muzabana is prohibited and invalid, and this is agreed upon by the four schools of Islamic jurisprudence: Hanafi [306] - Al-Muzabana, according to the Hanafi school, is classified as a corrupt sale, while the majority consider it to be an invalid sale. See: "Tabyin Al-Haqaiq" by Al-Zaylai (4/47); "Al-Bahr Al-Raiq" by Ibn Nujaym (6/82) , Maliki [307] -"Al-Kafi" by Ibn Abd Al-Barr (2/652). See: "Al-Dhakira الذخيرة " by Al-Qarafi  القرافي (5/392). , Shafi'i [308] -"Tuhfat al-Muhtaj "by Ibn Hajar Al-Haytami (4/471); "Nihayat Al-Muhtaj" by Al-Ramli (4/157). , and Hanbali [309] - "Iqna' " by Al-Hajjawi (2/117); "Kashaf al-Qina' "by Al-Buhuti (3/258). .

The Evidences:
Firstly: From the Sunnah:
On the authority of Jabir ibn Abdullah (رضي الله عنهما), he said: “The Messenger of Allah صلى الله عليه وسلم forbade muhaqala, muzabana, mu'awama, and mukhabara—one of them said: selling for years is mu'awama—and also forbade thunaya, and permitted ariyya sales. [310] - Narrated by Muslim (1537). ”
Reasoning:
The Prophet صلى الله عليه وسلم prohibited muzabana, and the prohibition indicates impermissibility and invalidity [311] - See: "Kashaf al-Qina' "by Al-Buhuti (3/258) .
Secondly: The sale of muzabana involves Riba (Usury) due to the lack of equivalence or the ignorance of its equality [312] -See: "Al-Majmu' " by Al-Nawawi (9/309), "Kashaf al-Qina' "by Al-Buhuti (3/258) .