(44) باب الْبَيِّعَانِ بِالْخِيَارِ مَا لَمْ يَتَفَرَّقَا
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.320).
Reference: Sahih al-Bukhari 2111
In-book reference: Book 34, Hadith 64
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 3, Book 34, Hadith 324