Sunan Ibn Majah, Book 12, Hadith 2299 (In-Book) ⓘ
It was narrated from Ibn 'Umar that the Messenger of Allah said: "Do not sell fruits until they have ripened." And he forbade (both) the seller and the purchaser (to engage in such a transaction).
حَدَّثَنَا مُحَمَّدُ بْنُ رُمْحٍ، أَنْبَأَنَا اللَّيْثُ بْنُ سَعْدٍ، عَنْ نَافِعٍ، عَنِ ابْنِ عُمَرَ، عَنْ رَسُولِ اللَّهِ ـ صلى الله عليه وسلم ـ قَالَ " لاَ تَبِيعُوا الثَّمَرَةَ حَتَّى يَبْدُوَ صَلاَحُهَا " . نَهَى الْبَائِعَ وَالْمُشْتَرِيَ .
also referenced under: Hadith 2214 (Reference) & Volume 3, Book 12, Hadith 2214 (DarusSalam)