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.'
It was narrated that Simak bin Harb said: I heard Malik Abu Safwan bin 'Umairah, say: 'I bought a pair of trousers from the Messenger of Allah (ﷺ) before the Hijrah, and he weighed it for me and allowed more. '
It was narrated from Jabir bin 'Abdullah that the Messenger of Allah (ﷺ) said: When you weigh, allow more.