You shall not have in your bag two kinds of weights, a large and a small. You shall not have in your house two kinds of measures, a large and a small. A full and just weight you shall have, a full and just measure you shall have; that your days may be prolonged in the land which the LORD your God gives you. For all who do such things, all who act dishonestly, are an abomination to the LORD your God (Deuteronomy 25:13-16).
This instruction is found in a large section of legislation given to the people of Israel as part of the covenant God initiated with them. In Deuteronomy, a code of behavior is set forth that articulates the nation's distinct relationship with God.
Yet interspersed between these laws dealing with major issues, we find several regulations regarding what would be considered rather commonplace occurrences. This particular instruction deals with the basic flow of commerce. In the world of Deuteronomy, most every transaction in the marketplace involved using balancing scales with standardized weights to measure out quantities of goods for buying or selling. It could be very easy to increase profit margins surreptitiously by altering the weight of one's stones, using a heavier stone to get more for one's money when buying and a lighter stone to give customers less for theirs. Obviously this is not ethical, but one might question how much might be gained by such a practice as the fraudulent stones had to be close enough to the standard weight to convince the other party that the transaction was legitimate. The gains per transaction probably amounted to a very incidental amount, making this the kind of offense that would give rise to some head-shaking with the acknowledgement that, while wrong, it is not that big a deal, as many might have done it.
But it is important for us not to rationalize such infractions, because Scripture assigns them gravity. Verse 16 does not say: “It's not that big a deal”; instead it says: “All who do such things, all who act dishonestly, are an abomination to the Lord your God.” This is strong language – an abomination? There are other practices in Deuteronomy that are described as abominable, practices with a more readily identifiable detestable nature such as sorcery, idolatry, and offering children in pagan rites. It is among such company that the law places one who cheats another out of a few cents in business. Such an action is an abomination to God, it is repugnant to him and an insult to his character if one names his name, yet engages in this practice. — A submission by Rolf Geyling.