(Mishnah): In a place where they normally measure in big Kelim...

(Beraisa): In a place where people sell even measures, he should not give a heaping measure, or vice-versa - "Eifah Shelemah" (the measure should be full);

If one says (in a place where people give a heaping measure) 'I will give an even measure and deduct from the price', or (in a place where they sell evenly) 'I will take a heaping measure and pay more, we do not allow this - "Eifah Shelemah va'Tzedek Yihyeh Lach." (This could lead to swindling, if onlookers do not know that there was compensation for the deviation from the custom.)

(Beraisa): In a place where they are Machri'a, one may not weigh evenly, and vice-versa - "Eifah Shelemah";

If one says 'I will deviate from the custom and compensate for this', we do not allow this - "Eifah Shelemah va'Tzedek Yihyeh Lach"

(Beraisa): "Lo Yihyeh Lecha" teaches that we appoint people to inspect and punish for false measures, but (reasoning says,) not for prices. (If one charges too much, people will buy from others.)

The Nasi's house appointed people to supervise measures and prices.

Shmuel told Karna to teach them that we appoint for measures, but not for prices. Karna taught that we appoint for measures and prices.

Shmuel cursed Karna, that a Keren (horn) should grow between his eyes. This was fulfilled.

Question: Like whom does Karna hold?

Answer: He holds like R. Yitzchak.

(R. Yitzchak): We appoint for measures and prices, due to swindlers.

(Beraisa): If one wanted to buy a liter, half or quarter liter, we measure that amount for him.

Question: What is the Chidush?

Answer: We make measures of these sizes (but not of other sizes. If there were measures of sizes close to each other, a seller could use the slightly smaller measure, and the buyer would not know that he got too little.)

(Beraisa): If one wanted to buy three quarters of a liter, we do not weigh for him a quarter liter three times (for we are careful not to give less, and he profits from the inaccuracies). Rather, we put a quarter liter weight with the meat and weigh it against a liter.

(Beraisa): If one wanted to buy 10 liters, we do not weigh for him a liter 10 times (with a Hachra'ah each time, like above). Rather, we weigh it all at once, there is only one Hachra'ah).

(Beraisa): A (hanging) scale should be at least three Tefachim below the ceiling and at least three above the ground (lest it hit the ceiling or floor during the Hachra'os);

The crossbar and two ropes (from which the pans hang) should be 12 Tefachim (four Tefachim each).

A scale of people who sell wool or glass should be at least two Tefachim from the ceiling and ground (less Hachra'ah is needed for lighter things). The crossbar and two ropes should be nine Tefachim (three each).

A scale of a grocer or regular person should be at least one Tefach from the ceiling and ground. The crossbar and ropes should be six Tefachim (two each).

A scale of one who sells gold and silver should be at least three fingers from the ceiling and ground. I do not know the length of the crossbar and ropes.

Question: What is the use of the first scale mentioned?

Answer (Rav Papa): It is for smiths of iron and copper.

(Rav Mani bar Patish): One may not use a scale that is too small. Likewise, it does not receive Tum'ah.

Question: We already learn this from a Mishnah!

(Mishnah): The string from which the scale of a grocer or regular person hangs must be at least a Tefach (for it to receive Tum'ah).

Answer: The Mishnah teaches only how low it must hang. Rav Mani teaches that also the crossbar and ropes must have the above Shi'ur (two Tefachim each) for it to receive Tum'ah.

(Beraisa): We do not make weights out of tin, lead or other metals (because they decrease in weight). One may make them from rock or glass.

(Beraisa): A Machak (a rod used to scrape off the excess from a measure) should not be made of gourd wood (it is too light, so its middle does not bend down enough to scrape off the proper amount), nor of metal (it is too heavy, it bends down and scrapes off too much);

Rather, it should be made of olive, sycamore or box wood.

(Beraisa): The thickness of a Machak should be the same on both sides (like the local custom. A thin Machak scrapes off more than a thick one. We are concerned lest he use the thin side when selling, and the thick side when buying);

One may not scrape quickly all at once, for this does not scrape off enough, nor very slowly, for this scrapes off too much. (Rather, he sweeps gently, in one or two sweeps).

R. Yochanan Ben Zakai: Woe to me if I teach these laws, and woe if I do not!

Woe if I teach them, lest swindlers learn how to cheat!

Woe if I do not teach them, lest swindlers think that Chachamim do not understand their ruses!

Question: Did he teach them?

Answer (Rav Shmuel bar Rav Yitzchak): Yes - "Yesharim Darchei Hash-m v'Tzadikim Yelchu Vam u'Foshe'im Yikashlu Vam."

(Beraisa): "Lo Sa'asu Avel ba'Mishpat ba'Midah ba'Mishkal uva'Mesurah":

'Ba'Midah' refers to measuring land. If two should divide evenly, one may not measure for one in winter and for the other in summer. (Rashbam - the rope (is moister and) stretches more in winter; R. Chananel - the land is more constricted in winter.)

'Ba'Mishkal' - one may not store his weights in salt. (Rashbam - this makes them heavier; Tosfos - this makes them lighter.)

'Uva'Mesurah' - one may not make a liquid foam when pouring it into the measure. (It will appear full even though it is not full; some explain, one may not heat the liquid before pouring it.)

We learn a Kal va'Chomer. Meshurah is a tiny measure, one part in 36 of a Lug, yet the Torah demands that the full measure be given, and all the more so it is insistent about bigger measures!

(Rav Yehudah): One may not keep a measure that is too big or too small in his house, even to use for a urinal (lest he wash it and use it to measure).

(Rav Papa): This is only in a place where the government does not give a seal of authentication on measures. Where it does, he may keep an incorrect measure. People will demand an authenticated measure.

Even where the government does not give seals, in a place where people are appointed to inspect measures (and punish for false measures), we are not concerned.

Rejection: This is wrong. We are concerned lest the measure be used just before Shabbos, when the inspectors are not around (R. Chananel; Rashbam - even where the government authenticates measures, it is forbidden, for buyers will not be careful just before Shabbos).