[Machine] "That the Messenger of Allah ﷺ said: 'None of you should sell something that another person has already bought.' This is narrated in Sahih Hadith of Malik, and Imam Shafi'i (may Allah have mercy on him) also endorsed it. It applies to anyone who buys an item from someone, and they have not separated (from each other) until another person comes to him and offers him the same item or something better than it at a lower price. In this case, the seller can revoke the sale because he still has the option before the separation. If this happens, it will be considered corruption, even though Allah has forbidden disobedience when one has knowledge of the Hadith, and the sale in this case becomes obligatory."  

أَنَّ رَسُولَ اللهِ ﷺ قَالَ لَا يَبِيعُ بَعْضُكُمْ عَلَى بَيْعِ بَعْضٍ أَخْرَجَاهُ فِي الصَّحِيحِ مِنْ حَدِيثِ مَالِكٍ وَقَدْ حَمَلَهُ الشَّافِعِيُّ رَحِمَهُ اللهُ عَلَى مَنِ اشْتَرَى مِنْ رَجُلٍ سِلْعَةً فَلَمْ يَتَفَرَّقَا حَتَّى أَتَاهُ آخَرُ فَعَرَضَ عَلَيْهِ مِثْلَ سِلْعَتِهِ أَوْ خَيْرًا مِنْهَا بِأَقَلَّ مِنَ الثَّمَنِ فَيَفْسَخُ بَيْعَ صَاحِبِهِ فَإِنَّ لَهُ الْخِيَارَ قَبْلَ التَّفَرُّقِ فَيَكُونُ هَذَا فَسَادًا وَقَدْ عَصَى اللهَ إِذَا كَانَ بِالْحَدِيثِ عَالِمًا وَالْبَيْعُ فِيهِ لَازِمٌ