Tirmidhi

(1) This hadith is explicit evidence for "separation by bodies" (tafarraq bil-abdan), meaning physically and bodily separating from one another. Some people hold the view that after a transaction is settled in a gathering, if other conversations begin within that same gathering, the option (of annulment) ends—that is, these individuals are proponents of "separation by statements" (tafarraq bil-aqwal). The aforementioned hadith clearly refutes their view, which is based purely on opinion. The truth is that the view of separation by statements is, in light of the evidences, outweighed and also contrary to the explicit hadith.

(2) This blessed hadith also establishes that if, within the same gathering, one party gives the other the option to make a decision right then and there, and then the transaction is concluded, their option (of annulment) will now end, no matter how long the gathering continues.

(3) This blessed hadith also indicates this important issue: that it is necessary for both the seller and the buyer to have goodwill towards each other. Therefore, it is not permissible for either of them to hasten the transaction in order to finalize it, nor for either party to immediately leave the gathering as soon as the deal is settled, thereby not giving the other party an opportunity to think and reflect. The result of this would be that the person may regret and feel remorse over his decision. Therefore, it is necessary that each of them gives the other companion time to consider and reflect.

(4) It is not permissible to deceive anyone "out of fear of return," since the right of return remains as long as the gathering continues. Attempting to nullify this right also falls under the category of usurping rights. Sincerity and goodwill towards the other party require that he be given full opportunity to exercise his right. The final words of the hadith are explicit evidence that the option of the gathering (khiyar al-majlis) is being established here, and as long as they are physically together, this right remains; otherwise, what would be the meaning of prohibiting separation?

Takhrij:
«أخرجه أبوداود، البيوع، باب في خيار المتبايعين، حديث:3456، والترمذي، البيوع، حديث:1247، والنسائي، البيوع، حديث:4488، وأحمد:2 /183.»©Explanation:
In this hadith as well, the mention of "khiyar al-majlis" (the option of cancellation while still in the meeting) is present.
Khiyar al-majlis is established according to most of the Companions and Followers (Tabi'in), as well as Imam Shafi'i and Imam Ahmad rahimahumullah. However, Imam Malik and Imam Abu Hanifah rahimahumallah do not accept it, even though the previous hadith serves as a clear textual proof on this issue.
Shaykh al-Hind Mawlana Mahmud al-Hasan (Deobandi) has stated that the truth and justice in this matter is that, in terms of evidence, the opinion of Imam Shafi'i rahimahullah is the stronger one.
Hazrat Shah Waliullah Muhaddith Dehlawi rahimahullah has also considered this to be the stronger view. However, for us who are followers (muqallid), there is no alternative but to adhere to the imitation (taqlid) of Imam Abu Hanifah rahimahullah.
See: (Taqrir Tirmidhi)