Sunan an-Nasa'i 4599
سنن النسائي#4599Sahihأَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا سُفْيَانُ، عَنِ ابْنِ طَاوُسٍ، عَنْ طَاوُسٍ، قَالَ سَمِعْتُ ابْنَ عَبَّاسٍ، يَقُولُ أَمَّا الَّذِي نَهَى عَنْهُ رَسُولُ اللَّهِ صلى الله عليه وسلم أَنْ يُبَاعَ حَتَّى يُسْتَوْفَى الطَّعَامُ .
It was narrated that Tawus said:"I heard Ibn 'Abbas say: 'As for that which the Messenger of Allah forbade, (it is) selling before taking possession of food
Scholarly Authentication
The label above is the grade most of these scholars gave — one dissenting opinion no longer speaks for all of them. If any scholar calls a narration fabricated, that verdict is shown instead, whatever the others say. Each scholar's own wording:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiHasan
In-book reference: 44:151