From his father, from his grandfather, that the Messenger of Allah ﷺ said: "Both the buyer and the seller retain the option as long as they did not separate, unless they agreed to making it optional. And it is not lawful for him to separate from his companion, fearing that he will change his mind."
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ الْبَيِّعَانِ بِالْخِيَارِ مَا لَمْ يَتَفَرَّقَا إِلاَّ أَنْ تَكُونَ صَفْقَةَ خِيَارٍ وَلاَ يَحِلُّ لَهُ أَنْ يُفَارِقَ صَاحِبَهُ خَشْيَةَ أَنْ يَسْتَقِيلَهُ
"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."
أَنَّ النَّبِيَّ ﷺ قَالَ الْمُتَبَايِعَانِ بِالْخِيَارِ مَا لَمْ يَتَفَرَّقَا إِلاَّ أَنْ يَكُونَ صَفْقَةَ خِيَارٍ وَلاَ يَحِلُّ لَهُ أَنْ يُفَارِقَ صَاحِبَهُ خَشْيَةَ أَنْ يَسْتَقِيلَهُ
The Prophet ﷺ said: Both parties in a business transaction have a right to annul it so long as they have not separated unless it is a bargain with the option to annul is attached to it; and it is not permissible for one of them to separate from the other for fear that one may demand that the bargain be rescinded.
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ الْمُتَبَايِعَانِ بِالْخِيَارِ مَا لَمْ يَفْتَرِقَا إِلاَّ أَنْ تَكُونَ صَفْقَةَ خِيَارٍ وَلاَ يَحِلُّ لَهُ أَنْ يُفَارِقَ صَاحِبَهُ خَشْيَةَ أَنْ يَسْتَقِيلَهُ
"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." (Using translation from Nasāʾī 4483)
أَنَّ النَّبِيَّ ﷺ قَالَ الْبَائِعُ وَالْمُبْتَاعُ بِالْخِيَارِ حَتَّى يَتَفَرَّقَا إِلَّا أَنْ يَكُونَ سَفْقَةَ خِيَارٍ وَلَا يَحِلُّ لَهُ أَنْ يُفَارِقَهُ خَشْيَةَ أَنْ يَسْتَقِيلَهُ
The Prophet ﷺ said: Both parties in a business transaction have a right to annul it so long as they have not separated unless it is a bargain with the option to annul is attached to it; and it is not permissible for one of them to separate from the other for fear that one may demand that the bargain be rescinded. (Using translation from Abū Dāʾūd 3456)
أَنَّ رَسُولَ اللهِ ﷺ قَالَ «الْمُتَبَايِعَانِ بِالْخِيَارِ مَا لَمْ يَفْتَرِقَا إِلَّا أَنْ تَكُونَ صَفْقَةَ خِيَارٍ وَلَا يَحِلُّ لَهُ أَنْ يُفَارِقَ صَاحِبَهُ خَشْيَةَ أَنْ يَسْتَقِيلَهُ»
"البَيِّعَان بالخِيار ما لم يَتَفَّرقَا إِلا أنْ تَكُونَ صفقةُ خِيار ولا يَحِلُّ له أَن يُفَارِقَ صَاحِبَه خشيةَ أنْ يَسْتَقِيلَهُ".
"المُتَبَايَعَان بالخيارِ ما لَمْ يَتَفَرَّقَا إِلَّا أَن تَكُونَ صَفقَةَ خيَار، ولا يَحِل له أَن يُفارقَ صاحِبَهُ خَشْيَةَ أَنْ يَسْتَقِيلَهُ" .