IBNMAJAH 2230:
from ʿUthmān b. ʿAffān —
"I used to sell dates in the marketplace, and I would say: 'This was such and such an amount (when I bought it).' I Would give the purchaser a specific amount of dates according to the way it had been measured for me, and take my profit. Then I began to have some doubts about that, so I asked the Messenger of Allah ﷺ, and he said: ‘When you name the amount, measure it in front of the purchaser."'
ابن ماجة ٢٢٣٠:
عن عثمان بن عفان —
كُنْتُ أَبِيعُ التَّمْرَ فِي السُّوقِ فَأَقُولُ كِلْتُ فِي وَسْقِي هَذَا كَذَا فَأَدْفَعُ أَوْسَاقَ التَّمْرِ بِكَيْلِهِ وَآخُذُ شِفِّي فَدَخَلَنِي مِنْ ذَلِكَ شَىْءٌ فَسَأَلْتُ رَسُولَ اللَّهِ ﷺ فَقَالَ إِذَا سَمَّيْتَ الْكَيْلَ فَكِلْهُ
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