أَخْبَرَنَا أَحْمَدُ بْنُ حَرْبٍ، قَالَ حَدَّثَنَا قَاسِمٌ، عَنْ سُفْيَانَ، عَنِ ابْنِ طَاوُسٍ، عَنْ أَبِيهِ، عَنِ ابْنِ عَبَّاسٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " مَنِ ابْتَاعَ طَعَامًا فَلاَ يَبِيعُهُ حَتَّى يَكْتَالَهُ " .
It was narrated that Ibn 'Abbas said: "The Messenger of Allah said: 'Whoever buys food, let him not sell it until he has checked its weight."" Translation Not Available
Book Ref: Sunan An Nisai Book 44 Hadith 4597
Web Ref: Sunan An Nisai Vol 5 Book 44 Hadith 4601