Sahih al-Bukhari 2111
Book 34: Sales and Trade · Narrated by `Abdullah bin `Umar
Arabic
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، أَخْبَرَنَا مَالِكٌ، عَنْ نَافِعٍ، عَنْ عَبْدِ اللَّهِ بْنِ عُمَرَ ـ رضى الله عنهما ـ أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ " الْمُتَبَايِعَانِ كُلُّ وَاحِدٍ مِنْهُمَا بِالْخِيَارِ عَلَى صَاحِبِهِ مَا لَمْ يَتَفَرَّقَا، إِلاَّ بَيْعَ الْخِيَارِ ".
English translation
Narrated `Abdullah bin `Umar:Allah's Messenger (ﷺ) said, "Both the buyer and the seller have the option of canceling or confirming a bargain unless they separate, or the sale is optional." (See Hadith No)
Reference: Sahih al-Bukhari 2111, Book of Sales and Trade. English translation by Dr. Muhammad Muhsin Khan.