Sunan Ibn Majah, Volume 3, Book 12, Hadith 2222 (DarusSalam) ⓘ
It was narrated from Jabir bin 'Abdullah that the Messenger of Allah said: "When you weigh, allow more. "
حَدَّثَنَا مُحَمَّدُ بْنُ يَحْيَى، حَدَّثَنَا عَبْدُ الصَّمَدِ، حَدَّثَنَا شُعْبَةُ، عَنْ مُحَارِبِ بْنِ دِثَارٍ، عَنْ جَابِرِ بْنِ عَبْدِ اللَّهِ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ " إِذَا وَزَنْتُمْ فَأَرْجِحُوا " .
also referenced under: Hadith 2222 (Reference) & Book 12, Hadith 2307 (In-Book)