Mishkat al-Masabih
He said that God’s Messenger forbade selling a quantity of dates whose measure was unknown for a specific quantity of dates. Muslim transmitted it.
وَعَنْهُ قَالَ: نَهَى رَسُولُ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ عَنْ بَيْعِ الصُّبْرَةِ مِنَ التَّمْرِ لَا يُعْلَمُ مَكِيلَتُهَا بِالْكَيْلِ الْمُسَمَّى مِنَ التَّمْرِ. رَوَاهُ مُسلم
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