The Torah requires honest weights and measures (see Vayikra 19:36). The Mishna on today’s daf teaches that business people who sell items like wine or oil are required to clean their scales on a regular basis in order to ensure that their customers are not being cheated. There are three different types of sellers, and each has a different schedule for washing his weights and scales:
- The ba’al ha-bayit – the homeowner (in this context refers to the manufacturer) – the farmer who harvests his grain or produces wine from his grapes or oil from his olives, keeping enough for his own private needs and selling the rest to sitona’im.
- The siton – the wholesaler who purchases in bulk from the ba’al ha-bayit and sells to the ḥenvani
- The ḥenvani – the storekeeper, who purchases from the wholesaler and sells in small amounts out of his ḥanut, or store.
According to the Tanna Kamma of the Mishna, the ba’al ha-bayit must clean his scales once every twelve months, since he uses his scales only on rare occasions, while the siton must wash them every thirty days, since spills and other remnants will make the scales unreliable. Rabban Shimon ben Gamliel argues that the rule should be the other way around, that is, that the siton need clean his scales only once a year, while the ba’al ha-bayit must do so monthly. The Rashbam explains that the volume of business done by the siton helps keep the scales clean, since liquids will not have time to dry and congeal. The ba’al ha-bayit, on the other hand, does business only occasionally, so it is important that he make sure that nothing was left on his scales.
The Meiri offers a different explanation for Rabban Shimon ben Gamliel’s ruling. He argues that it is a question of ona’a – of unreasonably inflated profits, which are forbidden. Since the ba’al ha-bayit sells to just one person, if the scales are off, then there is great potential for unreasonable profit from this sale. The wholesaler, however, sells to many storekeepers, and even if there is a slight discrepancy in the weights, it will make only a very small difference to each purchaser – a small amount that will likely be forgiven.