[If] one sold wine or oil to another, and it appreciated or depreciated, if [it happened] before the measure was filled, [it belongs] to the seller; once the measure was filled, [it belongs] to the seller; once the measure was filled, [it belongs] to the buyer. If there was a middleman between them, [and] the barrel broke, it broke for the middleman.  He is obligated to let three drops drip out for him. [If] he turned it over and drained [it], it belongs to the seller. A storekeeper, however, is not obligated to let three drops drip out. R' Yehudah says: Only on the eve of the Sabbath, at dusk, is he exempt.

[If] someone sent his son to a storekeeper with a pundion in his hand, and he measured [out] for him an issar's worth of oil and gave him an issar, [if] he broke the jar or lost the issar, the storekeeper is liable. R' Yehudah exempts him because he sent him for that purpose. The Sages agree with R' Yehudah that when the jar is in the hand of the child and the storekeeper measured into it, the storekeeper is exempt.

A wholesaler must clean his measures once in thirty days; and a householder, once in twelve months. Rabban Shimon ben Gamliel says: The reverse is true. A storekeeper must clean his measures twice a week, wipe his weights once a week, and clean the scales for every weighing.

Rabban Shimon ben Gamliel said: In regard to what was this stated? In regard to moist [commodities]. However, [in the case] of dry [ones], it is not necessary.  He is obligated to overbalance [the scales] a handbreadth in [the buyer's] favor. [If] he was weighing for him evenly, he must give him the extra [weight]: one to ten for moist [commodities] and one to twenty for dry [ones]. [In] a place where it is customary to measure with a small [measure], he may not measure with a large one; with a large one, he may not measure with a small one. [In a place where it is customary] to level, he may not heap; to heap, he may not level.