Riba (usury) is one of the gravest major sins. The Shariah has forbidden all sales that involve a possibility of Riba and has permitted lawful sales that are free of Riba. The pre-Islamic era of ignorance was swarming with Riba-based sales, so Islam rectified and refined such sale transactions. In this Hadīth, the Tābi‘i Abu Nadrah al-Mundhir ibn Mālik al-‘Abdi narrates that he asked the Companion ‘Abdullah ibn ‘Abbās (may Allah be pleased with him and his father) about Sarf, which is selling an item for another of the same type with a surplus and an addition in the taken or given item, like selling a dinar for two dinars or a dirham for two dirhams; whether it is a Riba-based sale or not. Ibn ‘Abbās answered by saying that it is not Riba in case it is exchanged hand to hand, i.e., at the time that the act of selling took place. Ibn ‘Abbās (may Allah be pleased with him and his father) did not deem selling an item for another of the same type with a surplus Riba, and he believed that Riba is not unlawful except in case of a deferred payment. So, Abu Nadrah informed Abu Sa‘īd al-Khudri (may Allah be pleased with him) about the Fatwa of Ibn ‘Abbās, whereupon Abu Sa‘īd (may Allah be pleased with him) told him that he would write to Ibn ‘Abbās not to give such a Fatwa and would review it with him, clarify the truth, and advise him. Then, Abu Sa‘īd (may Allah be pleased with him) narrated his supporting reference and evidence in forbidding the Riba of surplus and addition. He swore and said: "By Allah, some of the boys of the Messenger of Allah (may Allah's peace and blessings be upon him)," who are the servants, "brought dry dates, but he rejected them," the Prophet (may Allah's peace and blessings be upon him) rejected them because they were not from the dry dates produced by their land and not the ones known among them. It was said to the Prophet (may Allah's peace and blessings be upon him): This year, the dry dates of Madīnah were of bad quality. So, the servant took some of the bad dry dates and exchanged them for others and brought those good dry dates to the Prophet (may Allah's peace and blessings be upon him) in return for the defective ones and gave the buyer an excess in the weight and amount of the defective dry dates. Thereupon, the Prophet (may Allah's peace and blessings be upon him) said: "You made an addition! You committed Riba (usury)! Do not approach this," i.e., what you did and the addition you made in the weight is from Riba. So, the Prophet (may Allah's peace and blessings be upon him) forbade him from eating from the dry dates he had brought. Then, the Prophet (may Allah's peace and blessings be upon him) said to him by way of teaching: "If you find some doubt about your dry dates, sell them and then buy the dry dates you like," thus, the Prophet (may Allah's peace and blessings be upon him) forbade him from taking dry dates for dry dates. So, if there was something wrong with his dry dates, he should first sell them for money, then buy with that money whatever he liked of the dry dates, and there should be no surplus between the two. It seems that Ibn ‘Abbās gave that Fatwa of permissibility based on the apparent indication of the Prophet's statement mentioned in the two Sahīh Collections: "Riba is only in Nasī’ah (deferred payment)." This apparently indicates exclusiveness, as if he said: There is no Riba except in the deferred payment. However, there is a report in the Sahīh Muslim Collection indicating that Ibn ‘Abbās reconsidered his stance regarding his Fatwa, as Abu as-Sahbā’ narrated: "That he asked Ibn ‘Abbās about it in Makkah, and he disliked it," i.e., he disliked the permissibility of surplus in Sarf. The Hadīth highlights the prohibition of Riba al-Fadl (usury of surplus). It indicates the invalidity of the transaction that involves Riba. It highlights the fact that the Shariah rulings are to be sought only through the Qur‘an and the Sunnah. It shows how the Companions used to correct each other whenever they made a mistake..