[Machine] I used to buy fabric and take it to a certain marketplace, where they would take it from me and make a profit. I mentioned this to the Prophet ﷺ , and he said, "If you buy fabric by weight, then weigh it and if you sell fabric by weight, then measure it." This narration is from Munqidh, the slave of Suraqah, who narrated it from Uthman.
كُنْتُ أَشْتَرِي الْأَوْسَاقَ فَأَجِيءُ بِهَا إِلَى سُوقِ كَذَا فَيَأْخُذُونَهَا مِنِّي كَيْلًا وَيُرْبِحُونَنِي فَذَكَرْتُ ذَلِكَ لِلنَّبِيِّ ﷺ فَقَالَ إِذَا ابْتَعْتَ كَيْلًا فَاكْتَلْ وَإِذَا بِعْتَ كَيْلًا فَكِلْ وَرُوِي عَنْ مُنْقِذٍ مَوْلَى سُرَاقَةَ عَنْ عُثْمَانَ