Sunan an-Nasai 19220
In-book no 4484أَخْبَرَنَا عَلِيُّ بْنُ حُجْرٍ، قَالَ حَدَّثَنَا هُشَيْمٌ، عَنْ يَحْيَى بْنِ سَعِيدٍ، قَالَ حَدَّثَنَا نَافِعٌ، عَنِ ابْنِ عُمَرَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " الْمُتَبَايِعَانِ لاَ بَيْعَ بَيْنَهُمَا حَتَّى يَتَفَرَّقَا إِلاَّ بَيْعَ الْخِيَارِ " .
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 )