´It was narrated from Yahaya, from 'Ubaidullah who said:` "Nafi narrated to me from Ibn 'Umar, tht the Messenger of Allah said: 'the two parties to a transaction both have the choice so long as they have not separated, or they have chosen." (Sahih )
Hadith ReferenceSunan an-Nasa'i / The Book of Financial Transactions / Hadith: 4471
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:متفق عليه