Sahih Muslim 1526
Sahih Muslim · Book 21: The Book of Transactions · It is invalid to sell goods before taking possession of them
Ibn 'Umar (Allah be pleased with them) reported Allah's Messenger (ﷺ) as saying,:
حَدَّثَنَا يَحْيَى بْنُ يَحْيَى ، وَعَلِيُّ بْنُ حُجْرٍ ، قَالَ يَحْيَى أَخْبَرَنَا إِسْمَاعِيلُ بْنُ جَعْفَرٍ ، وَقَالَ عَلِيٌّ حَدَّثَنَا إِسْمَاعِيلُ، عَنْ عَبْدِ اللَّهِ بْنِ دِينَارٍ ، أَنَّهُ سَمِعَ ابْنَ عُمَرَ ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنِ ابْتَاعَ طَعَامًا فَلاَ يَبِعْهُ حَتَّى يَقْبِضَهُ " .
He who bought foodgrain should not sell it until he had taken possession of it.