Deuteronomy 25:13
"Thou shalt not have in thy bag divers weights, a great and a small."
Cross References (ranked by relevance)
Proverbs 11:1
A false balance is abomination to the LORD: but a just weight is his delight.
Amos 8:5
Saying, When will the new moon be gone, that we may sell corn? and the sabbath, that we may set forth wheat, making the ephah small, and the shekel great, and falsifying the balances by deceit?
Proverbs 16:11
A just weight and balance are the LORD’s: all the weights of the bag are his work.
Proverbs 20:10
Divers weights, and divers measures, both of them are alike abomination to the LORD.