Sunan an-Nasa'i 4592
It was narrated that Suwaid bin Qais said:
"Makhrafah Al-Abdi and I brought some cloth from Hajar, and the Messenger of Allah came to us while we were in Mina where there w a man who weighed (goods) in return for payment. He bought some trousers from us, and said to the man who weighed: 'Weigh it, and allow more."'
أَخْبَرَنَا يَعْقُوبُ بْنُ إِبْرَاهِيمَ، قَالَ حَدَّثَنَا عَبْدُ الرَّحْمَنِ، عَنْ سُفْيَانَ، عَنْ سِمَاكٍ، عَنْ سُوَيْدِ بْنِ قَيْسٍ، قَالَ جَلَبْتُ أَنَا وَمَخْرَفَةُ الْعَبْدِيُّ، بَزًّا مِنْ هَجَرَ فَأَتَانَا رَسُولُ اللَّهِ صلى الله عليه وسلم وَنَحْنُ بِمِنًى وَوَزَّانٌ يَزِنُ بِالأَجْرِ فَاشْتَرَى مِنَّا سَرَاوِيلَ فَقَالَ لِلْوَزَّانِ ‏
"‏ زِنْ وَأَرْجِحْ ‏"‏ ‏.‏