Sunan an-Nasa'i · Hadith 4474
The Book of Financial Transactions - كتاب البيوع
أخبرنا علي بن حجر، قال حدثنا هشيم، عن يحيى بن سعيد، قال حدثنا نافع، عن ابن عمر، قال قال رسول الله صلى الله عليه وسلم " المتبايعان لا بيع بينهما حتى يتفرقا إلا بيع الخيار " .
It was narrated from Yahya bin Sa 'eed , who said: "Nafi narrated to us from Ibn 'Umar, who said: 'The Messenger of Allah said: There is no transaction between the two parties until they separate, unless they have chosen to conclude the transaction."" (Sahih )
Gradings are classical jarḥ-wa-taʿdīl, name-matched to a rijāl index (not individually re-verified).