258. Shortchanged: The prohibition against cheating others with weights and measures

We are specifically prohibited to cheat others by shorting them in anything that is measured, whether it’s a bolt of cloth or a pound of cole slaw. If it’s sold by length, weight or volume, we are responsible to see that our customers get what they paid for. To do otherwise is called “avel bamishpat,” a perversion of justice. That’s pretty stong terminology for a petty, passive offense that the customer might not even notice. The language of the verse likens the merchant to a judge because this is actually a very serious matter.

A merchant must familiarize himself with the proper tools of measurement for his trade and ensure that they are accurate (as we will see in the next mitzvah). If he does short someone, he does not pay double, as is the case with one who actively stole property. Rather, the merchant just has to make up the shortfall.

The reason for this mitzvah should be obvious enough. We have previously spoken of personal property rights and the various forms of theft. This is stealing, too.

This mitzvah applies to both men and women in all times and places. It is discussed in the Talmud in tractates Baba Metzia (61b) and Baba Basra (90a-b). It is codified in the Shulchan Aruch in Choshen Mishpat 231. It is #271 of the 365 negative mitzvos in the Rambam’s Sefer HaMitzvos and #83 of the 194 negative mitzvos that can be fulfilled today as listed in the Sefer HaMitzvos HaKatzar of the Chofetz Chaim.