That the Prophet ﷺ said: "They (the two) are not separate from a sale except in agreement.  

عَنِ النَّبِيِّ ﷺ قَالَ لاَ يَتَفَرَّقَنَّ عَنْ بَيْعٍ إِلاَّ عَنْ تَرَاضٍ  

"The Prophet ﷺ gave a Bedouin the option after a sale." This Hadith is Hasan Gharib.  

أَنَّ النَّبِيَّ ﷺ خَيَّرَ أَعْرَابِيًّا بَعْدَ الْبَيْعِ وَهَذَا حَدِيثٌ حَسَنٌ غَرِيبٌ