It was narrated from Ibn 'Umar that the Prophet (ﷺ) said:"Whoever buys food, let him not sell it until he has taken full possession of it."
حَدَّثَنَا سُوَيْدُ بْنُ سَعِيدٍ، حَدَّثَنَا مَالِكُ بْنُ أَنَسٍ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، أَنَّ النَّبِيَّ ـ صلى الله عليه وسلم ـ قَالَ " مَنِ ابْتَاعَ طَعَامًا فَلاَ يَبِعْهُ حَتَّى يَسْتَوْفِيَهُ " .
IbnMaja
The Chapters on Business Transactions • Hadith 2226