It was narrated that Suwaid bin Qais said:
"Makhrafah Al' Abdi and I brought linens from Hajar[1] The Messenger of Allah ﷺ came to us to bargain with us with some trousers. There was someone with me who weighed (the goods) in exchange for a wage. So the Prophet ﷺ said to the one weighing: 'Weigh and add more.'"

حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، وَعَلِيُّ بْنُ مُحَمَّدٍ، وَمُحَمَّدُ بْنُ إِسْمَاعِيلَ، قَالُوا حَدَّثَنَا وَكِيعٌ، حَدَّثَنَا سُفْيَانُ، عَنْ سِمَاكِ بْنِ حَرْبٍ، عَنْ سُوَيْدِ بْنِ قَيْسٍ، قَالَ جَلَبْتُ أَنَا وَمَخْرَفَةُ الْعَبْدِيُّ، بَزًّا مِنْ هَجَرَ فَجَاءَنَا رَسُولُ اللَّهِ ـ ﷺ ـ فَسَاوَمَنَا سَرَاوِيلَ وَعِنْدَنَا وَزَّانٌ يَزِنُ بِالأَجْرِ فَقَالَ لَهُ النَّبِيُّ ـ ﷺ ـ " يَا وَزَّانُ زِنْ وَأَرْجِحْ " .