Sunan an-Nasa'i 4519
سنن النسائي#4519Sahihأَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا اللَّيْثُ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ " لاَ تَبِيعُوا الثَّمَرَ حَتَّى يَبْدُوَ صَلاَحُهُ " . نَهَى الْبَائِعَ وَالْمُشْتَرِيَ .
It was narrated from Ibn 'Uar that the Messenger of Allah said:"Do not sell fruits until their condition is known. And he forbade (both) the seller and the purchaser (to engage in such a transaction)
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 ZaiIsnaad Sahih
In-book reference: 44:71