Bava Basra, chapter five, Mishnah 11 - the last in the chapter. The opening of the Mishnah serves as a sort of completion to the previous Mishnah, which stated: "Amar Rabbi Shimon: Bameh devarim amurim" - "Rabbi Shimon said: To what do these matters apply", meaning, in which cases do the principles mentioned regarding the cleaning of weights and measures apply.
Liquid and dry goods:
This applies to moist merchandise, which leaves behind residue: liquid that sticks to the wall of the vessel and coagulates, such as dried wine; or merchandise like fish and meat, which contain moisture. But with dry goods - such as one measuring rice and the like - the merchandise leaves no residue at all, and therefore the seller is not required to clean his measures and the pans of his scales. Up to this point, this is a direct continuation of the law of the previous Mishnah.
"Even sheleimah vatzedek yihyeh lach" - "A perfect and just weight you shall have":
From here, the Mishnah opens with a new topic. The verse states: "Even sheleimah vatzedek yihyeh lach" - "A perfect and just weight you shall have" - the weight stone must be complete and exact, and it must also be "just." The verse continues in the same way regarding an eifah, a measure of volume, stating that it too must be complete and just. The obvious question arises: what does the word "just" (tzedek) add? After all, "complete" (sheleimah) already implies exact and precise.
Rather, the Sages say that the word "just" comes to add an obligation to tip the scale - both literally and figuratively - in favor of the buyer. This justice requires giving the buyer slightly more than the exact amount. This provides an interesting reflection of the word "tzedek," which does not represent the strict letter of the law like "mishpat" (judgment), but rather shares a root with tzedakah (charity), implying a slight inclination for the benefit of others.
Two ways to give the buyer an extra amount:
To understand the words of the Mishnah, we must remember what these scales looked like: two pans suspended by strings from either end of a balance beam. The heavier of the two pans descends, and when weight is added to the other side, they balance out. From this, there emerge two ways to give the buyer an extra amount:
Tipping the scales: The seller places a litra weight on one side and places the merchandise against it, adding a little to it - until the scales tip in favor of the buyer.
An addition at the end of the measuring: The seller measures an exact litra ten times, gives the buyer the ten litras, and at the end adds a little extra into his vessel.
"Vechayav lehachria lo tefach" - And he is obligated to tip the scale a tefach for him:
The Mishnah deals first with a case of a single weighing, and establishes: "Vechayav lehachria lo tefach" - And he is obligated to tip the scale a tefach for him. A tefach is a measure of distance - about four inches, nearly ten centimeters - and we must ostensibly ask, how does a measure of length apply to a litra of rice? The answer is that when placing the merchandise on the scales, they must tip in such a way that the buyer's pan descends and sits about a tefach lower than the pan holding the weight. This is the tipping in his favor.
The Bartenura teaches that this obligation does not apply to every tiny amount. If a person buys a trivial item for a perutah, and the seller were to tip the scale for him, he would end up giving him far more than what is appropriate, which is unfair. Therefore, this law only applies to a purchase of at least a litra. The word litra comes from Latin - libra - which is conceptually similar to a pound, about 454 grams. Interestingly, this word also means scales, and it is the root of the English abbreviation for a pound: lb.
"Hayah shokel lo ayin be'ayin":
The second way is to weigh exactly and add afterward, as the Mishnah says: "Hayah shokel lo ayin be'ayin" - He would weigh it for him eye to eye. The simple meaning of the expression is eye opposite eye: just as the two eyes are aligned in a person's head at an equal height, with neither one higher nor lower than the other, so too the two pans of the scale stand opposite one another equally.
Therefore, when the buyer asks for a kilo of rice and the seller gives him an exact kilo, after he removes the merchandise from the scale and places it into the buyer's container - "nosen lo giromav" - he gives him his extra addition, adding a little bit for him, tipping the scale in his favor by way of an addition.
"Echad la'asarah belach ve'echad le'esrim bayavesh":
And how much should the addition be? Regarding this, the Mishnah states: "Echad la'asarah belach ve'echad le'esrim bayavesh" - One to ten for liquid and one to twenty for dry. The grammatical way to express one part of ten should have been "echad me'asarah" (one from ten), with the letter mem, whereas the Mishnah uses the phrase "echad la'asarah" (one to ten). This wording requires explanation.
Therefore, the Gemara says that we must read the words as if they said "echad me'asarah la'asarah" - one part from ten for every ten. It turns out that the measure of the addition for a liquid is one out of a hundred, about one percent.
And regarding dry goods, according to the approach of the Ritva, and similar to the words of the Gemara, one should read it as "echad me'esrim le'esrim" - one part from twenty for every twenty, which is one out of four hundred, about a quarter of a percent. In other words, one who measures rice adds a quarter of a percent.
The reason why liquid receives a larger addition is this: when pouring a liquid, a little bit of it remains stuck to the side of the container, and it turns out that the buyer receives slightly less. That percentage remains with the seller, not intentionally but because of its adherence to the side during the pouring - unlike dry goods, where at the time of pouring, every single grain spills out.
Everything is according to local custom:
Finally, the Mishnah concludes with the matter of custom, since all the laws of this Mishnah are practically determined according to what is customary in that place. There is a place where they are accustomed to measuring with a large measure, in a large measuring vessel - for someone coming to buy ten kilos, they take a large ten-kilo measuring vessel and fill it once. And there is a place where they are accustomed to measuring with a small measure, in a small one-kilo measuring vessel, and they fill it ten times.
The difference between them is that if one must leave an addition with each and every measurement, it turns out that measuring with a small vessel is to the buyer's advantage, since they add a little for him each time. And regarding this the Mishnah says: "Makom shenahagu lamod bedakah - lo yamod begasah" - In a place where they are accustomed to measure with a small measure, he may not measure with a large measure, and if the local custom is to measure with a large vessel - "lo yamod bedakah" - he may not measure with a small measure. Everything must be done according to the prevailing custom in that place.
And the same applies to one who comes to buy flour, let us say a cup of flour: one can fill the cup heaping, so that the contents rise above it in the shape of a mound, or one can strike it - leveling the surface of the measure to a flat surface. Here too, everything follows the custom: in a place where they are accustomed to strike, to level the surface of the vessel before giving it to the buyer - he must strike it and not make it heaping, and it is forbidden for him to give a heaping measure. And in a place where they are accustomed to make it heaping, where one cup means a heaping cup - he may not strike it, and he is not permitted to level its surface.
It should be noted that even when leveling the measure, since there is an obligation to give an extra amount, the intention is not to level it perfectly but rather approximately. This way, a tiny bit extra remains - that quarter of a percent or so - which is kept in the buyer's favor when pouring out the flour or any other merchandise.
In summary: In this Mishnah we learned that the obligation to clean the scales applies to liquids and not dry goods, and that the word "tzedek" in the verse adds an obligation to tip the scale in the buyer's favor. There are two ways to do this: tipping the scales a tefach in his favor (for a litra and above, according to the Bartenura), or weighing it exactly and giving him the extra addition - one percent for liquids and a quarter of a percent for dry goods. Finally, we saw that everything is determined by local custom: whether measuring with a thick or thin strike, and whether giving a heaped or leveled measure.
With this we have concluded the fifth chapter of Tractate Bava Basra, and from here we will continue on to the sixth chapter, with God's help.