Hakeem bin Hizam reported,

The Messenger of Allah ﷺ said, "The two parties to a sale each have the option to revoke it as long as they have not parted. If they are both truthful and disclose any defects, their transaction will be blessed, but if they conceal and lie, the blessing of their transaction will be wiped out."This is an authentic hadith.Something similar was reported from Abu Barza Aslami, that two men brought a dispute to him concerning a horse after they had completed the sale, and they were on a boat at the time. He said, "I do not see that the two of you have parted yet," and he cited that the Messenger of Allah ﷺ said, "The two parties to a sale each have the option as long as they have not parted."Some scholars from Kufa and elsewhere held that the parting takes place through speech alone. This is the view of Sufyan Thawri, and the same is reported from Malik bin Anas.It is reported that Ibn Mubarak said, "How can I reject this when the hadith concerning it from the Prophet ﷺ is authentic?" And he supported this view.The meaning of the Prophet's ﷺ words "except in a sale with the option" is that the seller offers the buyer a choice after the sale has been concluded. If he gives him the choice and the buyer chooses to confirm the sale, then he no longer has any option to cancel the sale afterward, even if they have not yet parted. This is how Shafii and others have explained it.Among the evidence that strengthens the view of those who say that parting is by physical separation rather than by speech is the hadith of Abdullah bin Amr from the Prophet ﷺ.

حدثنا محمد بن بشار حدثنا يحيى بن سعيد عن شعبة عن قتادة عن صالح أبي الخليل عن عبد الله بن الحارث

عن حكيم بن حزام قال

قال رسول الله ﷺ البيعان بالخيار ما لم يتفرقا فإن صدقا وبينا بورك لهما في بيعهما وإن كتما وكذبا محقت بركة بيعهما هذا حديث صحيح وهكذا روي عن أبي برزة الأسلمي أن رجلين اختصما إليه في فرس بعد ما تبايعا وكانوا في سفينة فقال لا أراكما افترقتما وقال رسول الله ﷺ البيعان بالخيار ما لم يتفرقا وقد ذهب بعض أهل العلم من أهل الكوفة وغيرهم إلى أن الفرقة بالكلام وهو قول سفيان الثوري وهكذا روي عن مالك بن أنس وروي عن ابن المبارك أنه قال كيف أرد هذا والحديث فيه عن النبي ﷺ صحيح وقوى هذا المذهب ومعنى قول النبي ﷺ إلا بيع الخيار معناه أن يخير البائع المشتري بعد إيجاب البيع فإذا خيره فاختار البيع فليس له خيار بعد ذلك في فسخ البيع وإن لم يتفرقا هكذا فسره الشافعي وغيره ومما يقوي قول من يقول الفرقة بالأبدان لا بالكلام حديث عبد الله بن عمرو عن النبي ﷺ