Hadith 2247, 2248 - Sales in which a Price is paid for Goods to be Delivered Later (As-Salam) - Sahih Al-Bukhari - صحيح البخاري - Collection of Actions, Sayings and Teachings of Prophet Muhammad (صلى الله عليه و سلم) - Kutub as-Sittah

35. Sales in which a Price is paid for Goods to be Delivered Later (As-Salam) - كتاب السلم

4) Chapter: As-Salam for (the fruits of) dat-palms

Narrated Abu Al-Bakhtari:

I asked Ibn `Umar about Salam (the fruits of) date-palms. He replied, "The Prophet (ﷺ) forbade the sale of dates till their benefit becomes evident and fit for eating and also the sale of silver (for gold) on credit." I asked Ibn `Abbas about Salam for dates and he replied, "The Prophet (ﷺ) forbade the sale of dates till they were fit for eating and could be estimated."

Reference: 2247, 2248
English reference: Vol. 3, Book 35, Hadith 451
In-book reference: Book 35, Hadith 10
Grade: Sahih
Read this hadith from Darussalam Collection

4) باب السَّلَمِ فِي النَّخْلِ

حَدَّثَنَا أَبُو الْوَلِيدِ، حَدَّثَنَا شُعْبَةُ، عَنْ عَمْرٍو، عَنْ أَبِي الْبَخْتَرِيِّ، قَالَ سَأَلْتُ ابْنَ عُمَرَ ـ رضى الله عنهما ـ عَنِ السَّلَمِ، فِي النَّخْلِ فَقَالَ نُهِيَ عَنْ بَيْعِ النَّخْلِ، حَتَّى يَصْلُحَ، وَعَنْ بَيْعِ الْوَرِقِ، نَسَاءً بِنَاجِزٍ‏.‏ وَسَأَلْتُ ابْنَ عَبَّاسٍ عَنِ السَّلَمِ، فِي النَّخْلِ، فَقَالَ نَهَى النَّبِيُّ صلى الله عليه وسلم عَنْ بَيْعِ النَّخْلِ حَتَّى يُؤْكَلَ مِنْهُ، أَوْ يَأْكُلَ مِنْهُ، وَحَتَّى يُوزَنَ‏.‏