Sahih al-Bukhari 2239
صحيح البخاري#2239Sahihحَدَّثَنَا عَمْرُو بْنُ زُرَارَةَ، أَخْبَرَنَا إِسْمَاعِيلُ ابْنُ عُلَيَّةَ، أَخْبَرَنَا ابْنُ أَبِي نَجِيحٍ، عَنْ عَبْدِ اللَّهِ بْنِ كَثِيرٍ، عَنْ أَبِي الْمِنْهَالِ، عَنِ ابْنِ عَبَّاسٍ ـ رضى الله عنهما ـ قَالَ قَدِمَ رَسُولُ اللَّهِ صلى الله عليه وسلم الْمَدِينَةَ، وَالنَّاسُ يُسْلِفُونَ فِي الثَّمَرِ الْعَامَ وَالْعَامَيْنِ ـ أَوْ قَالَ عَامَيْنِ أَوْ ثَلاَثَةً. شَكَّ إِسْمَاعِيلُ ـ فَقَالَ " مَنْ سَلَّفَ فِي تَمْرٍ فَلْيُسْلِفْ فِي كَيْلٍ مَعْلُومٍ، وَوَزْنٍ مَعْلُومٍ ".
Narrated Ibn `Abbas:Allah's Messenger (ﷺ) came to Medina and the people used to pay in advance the price of fruits to be delivered within one or two years. (The sub-narrator is in doubt whether it was one to two years or two to three years.) The Prophet (ﷺ) said, "Whoever pays money in advance for dates (to be delivered later) should pay it for known specified weight and measure (of the dates)
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:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 35:1