As-Salam for a known specified weight Sahih al-Bukhari 2241
Arabic hadith text
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 ".
Translation
Narrated Ibn `Abbas
The Prophet (ﷺ) 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.