Sahih al-Bukhari, Book 35, Hadith 5 (In-Book) ⓘ
Narrated Ibn `Abbas: The Prophet came (to Medina) and he told the people (regarding the payment of money in advance that they should pay it) for a known specified measure and a known specified weight and a known specified period.
حَدَّثَنَا قُتَيْبَةُ، حَدَّثَنَا سُفْيَانُ، عَنِ ابْنِ أَبِي نَجِيحٍ، عَنْ عَبْدِ اللَّهِ بْنِ كَثِيرٍ، عَنْ أَبِي الْمِنْهَالِ، قَالَ سَمِعْتُ ابْنَ عَبَّاسٍ ـ رضى الله عنهما ـ يَقُولُ قَدِمَ النَّبِيُّ صلى الله عليه وسلم وَقَالَ " فِي كَيْلٍ مَعْلُومٍ وَوَزْنٍ مَعْلُومٍ إِلَى أَجَلٍ مَعْلُومٍ " .
also referenced under: Hadith 2241 (DarusSalam) & Volume 3, Book 35, Hadith 445 (USC-MSA)