Sahih al-Bukhari 2082
Narrated Hakim bin Hizam:
The Prophet (ﷺ) aid, "The buyer and the seller have the option to cancel or to confirm the deal, as long as 
they have not parted or till they part, and if they spoke the truth and told each other the defects of the 
things, then blessings would be in their deal, and if they hid something and told lies, the blessing of 
the deal would be lost."
حَدَّثَنَا بَدَلُ بْنُ الْمُحَبَّرِ، حَدَّثَنَا شُعْبَةُ، عَنْ قَتَادَةَ، قَالَ سَمِعْتُ أَبَا الْخَلِيلِ، يُحَدِّثُ عَنْ عَبْدِ اللَّهِ بْنِ الْحَارِثِ، عَنْ حَكِيمِ بْنِ حِزَامٍ ـ رضى الله عنه ـ عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ ‏
"‏ الْبَيِّعَانِ بِالْخِيَارِ مَا لَمْ يَتَفَرَّقَا ـ أَوْ قَالَ حَتَّى يَتَفَرَّقَا ـ فَإِنْ صَدَقَا وَبَيَّنَا بُورِكَ لَهُمَا فِي بَيْعِهِمَا، وَإِنْ كَتَمَا وَكَذَبَا مُحِقَتْ بَرَكَةُ بَيْعِهِمَا ‏"‏‏.‏