Deuteronomy 25:16

Injustice. Proverbs xx. 10. To have a greater weight for buying and a less one for selling, is the way to grow rich here, or to obtain the mammon of iniquity; though, when such mean practices are detected, the man who cheats often loses more than he had gained; and at any rate, must either make restitution, if possible, or receive the wages of his unjust labour and craft in the world to come. (Haydock)