Dalil

Quran Al-Isra 17:35

وَأَوۡفُواْ ٱلۡكَيۡلَ إِذَا كِلۡتُمۡ وَزِنُواْ بِٱلۡقِسۡطَاسِ ٱلۡمُسۡتَقِيمِۚ ذَٰلِكَ خَيۡرٞ وَأَحۡسَنُ تَأۡوِيلٗا

Translation

And give full measure when you measure, and weigh with an even [i.e., honest] balance. That is the best [way] and best in result.