Hadith 1352B1

قَالَ مَالِك : الْأَمْرُ عِنْدَنَا فِيمَنْ سَلَّفَ فِي طَعَامٍ بِسِعْرٍ مَعْلُومٍ إِلَى أَجَلٍ مُسَمًّى، فَحَلَّ الْأَجَلُ فَلَمْ يَجِدِ الْمُبْتَاعُ عِنْدَ الْبَائِعِ وَفَاءً مِمَّا ابْتَاعَ مِنْهُ فَأَقَالَهُ، فَإِنَّهُ لَا يَنْبَغِي لَهُ أَنْ يَأْخُذَ مِنْهُ إِلَّا وَرِقَهُ أَوْ ذَهَبَهُ أَوِ الثَّمَنَ الَّذِي دَفَعَ إِلَيْهِ بِعَيْنِهِ، وَإِنَّهُ لَا يَشْتَرِي مِنْهُ بِذَلِكَ الثَّمَنِ شَيْئًا حَتَّى يَقْبِضَهُ مِنْهُ، وَذَلِكَ أَنَّهُ إِذَا أَخَذَ غَيْرَ الثَّمَنِ الَّذِي دَفَعَ إِلَيْهِ، أَوْ صَرَفَهُ فِي سِلْعَةٍ غَيْرِ الطَّعَامِ الَّذِي ابْتَاعَ مِنْهُ فَهُوَ بَيْعُ الطَّعَامِ قَبْلَ أَنْ يُسْتَوْفَى .
Imam Malik, may Allah have mercy on him, said: In our view, the ruling is as follows: Whoever gives advance payment (salam) for grain at a fixed price for a specified period, then when the period ends and the buyer does not find the grain with the seller and the salam is broken, the buyer should take back exactly the silver or gold or the price he had given. He should not purchase another item from the seller in exchange for it until he takes possession of his payment, because if the buyer takes something other than what he had paid and buys another item in exchange for it, then he has sold the grain before taking possession of it, and the Messenger of Allah, peace and blessings be upon him, has prohibited this.
Hadith Reference موطا امام مالك رواية يحييٰ / كتاب البيوع / 1352B1
Hadith Takhrij «فواد عبدالباقي نمبر: 31 - كِتَابُ الْبُيُوعِ-ح: 49»