Narrated by Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: When the buyer and the seller have a dispute and neither of them has evidence (to support their claim), while the goods are still in their original condition, then the statement of the owner of the goods will be trusted, or both will return the transaction.

Abdul Malik bin Ubaid says: I was present with Abu Ubaidah bin Abdullah bin Mas'ud when two men came to him. They had made a transaction for some goods, but the buyer claimed that he had bought the goods for a certain amount, and the seller claimed that he had sold it for a different amount. Abu Ubaidah said: A similar issue was brought to our master Abdullah bin Mas'ud (may Allah be pleased with him). He said: I was present with the Messenger of Allah (peace and blessings be upon him) when a similar issue was presented to him. The Messenger of Allah (peace and blessings be upon him) ordered the seller to swear an oath on his claim, then gave the buyer the choice: if he wished, he could take the goods at that price, and if he wished, he could cancel the transaction altogether.

. (Second chain) Abdullah bin Imam Ahmad says: I read this chain to my respected father: I have been informed by Hisham bin Yusuf about those who buy and sell, this is the hadith of Ibn Jurayj, he narrates from Ismail bin Umayyah, and he from Abdul Malik bin Ubaid, but my father Imam Ahmad said: Hajjaj A‘war said: Abdul Malik bin Ubaidah said: Hashim narrated to us, he said: Ibn Abi Layla narrated to us from Qasim bin Abdur Rahman, and he narrated from our master Ibn Mas‘ud (may Allah be pleased with him), in this there are no words of ‘from his father’ (عَنْ اَبِیْہِ).

Narrated from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: When two people involved in buying and selling have a dispute, then the statement of the seller will be trusted, and the buyer will have the choice (whether he wants to keep the deal or cancel it).

Qasim says: There was a disagreement between Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) and Sayyiduna Ash'ath bin Qais (may Allah be pleased with him). The former said: It is of ten, but the latter said: It is of twenty. Sayyiduna Ibn Mas'ud (may Allah be pleased with him) said: Appoint someone between me and yourself (so that he may decide). Sayyiduna Ash'ath (may Allah be pleased with him) said: I appoint you yourself. Hearing this, Sayyiduna Ibn Mas'ud (may Allah be pleased with him) said: Then I will decide as the Messenger of Allah (peace and blessings be upon him) decided. The Messenger of Allah (peace and blessings be upon him) said: When there is a disagreement between two people involved in a transaction, and neither has any evidence, then the statement of the seller will be relied upon, or both may annul the sale.