(11) باب وُجُوبِ الْخِيَارِ لِلْمُتَبَايِعَيْنِ قَبْلَ افْتِرَاقِهِمَا بِأَبْدَانِهِمَا
It was narrated from 'Amr bin Shu'aib, from his father , form his grandfather, that the Prophet said:
"The two parties to a transaction have the choicer so long as they have not separated, unless they reach an agreement before parting, and it is not permissible to hasten to leave for fear that the other party may change his mind."
Reference: Sunan an-Nasa'i 4483
In-book reference: Book 44, Hadith 35
English translation: Vol. 5, Book 44, Hadith 4488