Bava Batra

and an 'Ukla. — How much is an 'ukla? — A fifth of a quarter [of a kab]. In the case of liquid measures one may make a hin,  half a hin, a third of a hin, a quarter of a hin, a log,  half a log, a quarter [of a log], an eighth [of a log], and an eighth of an eighth [of a log] which is a kortob.  [Why should] one [not be allowed] also to make a two-kab [measure]?  — It might be mistaken  for a tarkab.  This proves that people may err by a third;  [but] if so, one kab [measure] also should not be made, since it might be mistaken  for half a tarkab?  — But this is the reason why a two-kab [measure] must not be made; it might be mistaken  for half a tarkab. This proves that one may err by a quarter;  [but] if so, half a toman and an ukla [measures, also,] should not be made?  — R. Papa replied: People are familiar with small measures [and are not likely to mistake them for one another]. Should not one be forbidden to make a third of a hin [and] a quarter of a hin?  — Since these [measures] were [used] in the Temple, the Rabbis have not enacted any precautionary prohibitions against their use. Let precautionary prohibitions be adopted in the case of the Temple [itself]? — Priests are careful. Samuel said:  Measures must not be increased [even when all the townspeople have agreed to alter the standards of the measures] by more than a sixth, nor [even by general consent] may [the value of] a coin [be increased by] more than a sixth. And any profits on sales must not exceed one sixth. What is the reason why measures must not be increased by more than a sixth? If it is said, because market prices will rise [above due proportions],  [then for the same reason one should] not [be allowed to increase] even [by] a sixth! But if [it be said], because of the overcharge,  so that the entire purchase should not have to be cancelled;  surely, Raba said: One may withdraw [from any transaction in which] anything [had been sold] by measure, weight or number, even [if the overcharge was] less than [the legal limit of] overcharge!  But [if it be said that the reason why no more than a sixth may be added to weights is] that the dealer may not incur any loss;  [has this law, then, been made, it may be retorted, on the assumption that a dealer] must incur no loss [but also] requires no profit? 'Buy and sell [at no profit] and be called a merchant!' — But, said R. Hisda: Samuel found a Scriptural text and expounded it. [It is written], And the shekel shall be twenty gerahs; twenty shekels, five and twenty shekels, ten and five shekels, shall be your maneh.