Sunan an-Nasa'i 4477
سنن النسائي#4477Sahihأَخْبَرَنَا عَبْدُ الْحَمِيدِ بْنُ مُحَمَّدٍ، قَالَ حَدَّثَنَا مَخْلَدٌ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنْ عَمْرِو بْنِ دِينَارٍ، عَنِ ابْنِ عُمَرَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " كُلُّ بَيِّعَيْنِ لاَ بَيْعَ بَيْنَهُمَا حَتَّى يَتَفَرَّقَا إِلاَّ بَيْعَ الْخِيَارِ " .
It was narrated from Sufyan, from 'Amr bin Dinar, from Ibn 'Umar, who said:the Messenger of Allah said: "When two people meet to engage in trade, the transaction between them is not binding until they separate, unless they have chosen to concluded the transaction
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
In-book reference: 44:29