The Torah commands toward the end of Parashat Kedoshim (Vayikra 19:25), “Lo Ta’asu Avel Ba’mishpat, Ba’mida Ba’mishkal U’bamesura” – “Do not make a perversion in judgment: in measurement, weight, or volume.” This verse introduces the prohibition against cheating people by using inaccurate weights and measures.
The Gemara explains that the word “Mesura” refers to a volume of liquid equaling 1/33rd of a Log. A Log is just 11.7 ounces, and thus a “Mesura” is an exceedingly small volume. The Torah specified this volume to show that when it comes to weights and measures, even the slightest discrepancy is forbidden and violates this Biblical prohibition. Whereas the prohibition against direct theft is transgressed only if one stole at least the value of a “Peruta” (the smallest unit of Talmudic currency), the prohibition against dishonest weights and measures is violated through even a minimal distortion.
Significantly, the Torah introduces this command by stating, “Lo Ta’asu Avel Ba’mishpat” – referring to weights and measures as “Mishpat” (“judgment”). The Sefer Ha’hinuch explains that anytime one weights or measures something for commercial purposes, he is, in effect, “judging,” as he is determining how much the other party needs to pay. As such, one who uses inaccurate weights and measures is no different from a judge who knowingly perverts justice by ruling incorrectly, based on personal biases. The Torah regards the perversion of justice as among the most grievous sins, referring to an individual guilty of this offense as a “Meshukatz” (despicable person) and a “Toeba” (abomination). Furthermore, the Sages warn of five grave consequences of the sin of dishonest weights and measures – it defiles the Land of Israel, defames the Name of G-d, causes the Shechina to leave, causes the Jewish People to be defeated by their enemies, and causes our nation’s exile.
The Gemara comments that the punishment for this sin is even more severe than the punishment of the Arayot – forbidden intimate relationships. Moreover, this violation is far more difficult to atone for than Arayot. A sin involving Arayot is an offense “Ben Adam La’makom” – between a person and G-d – and can thus be atoned with relative ease, through the process of sincere repentance. Using false weights and measures, however, is an offense against other people, and thus atonement requires making restitution and asking the victims for forgiveness.
However, unlike a thief, who is required to pay the victim twice the amount he stole (“Kefel”), one who deceives people through the use of false weights and measures is required to pay only the amount he received from them unlawfully.
The Sages enacted a number of different safeguards to protect against this violation. For example, if a person’s scale or other device was chipped or otherwise became defective, he may not use it even accurately, adjusting the weight or measure to account for the defect. Although he will not be cheating his customers, nevertheless, it is likely that the device will be worn further with time, such that the proprietor will unknowingly be cheating his customers, and it therefore may not be used. Another example has to do with the ropes used for measuring land. If two brothers inherit a property and divide it between them, and Bet Din measures the two halves to ensure they are precisely equal, the Bet Din must measure both in the same season. The Gemara explains that ropes slightly contract in the summer heat, and thus if one property is measured in the winter and the other in the summer, one of the brothers will be receiving a slightly larger portion than the other. Although the discrepancy would be minimal, nevertheless, the Sages wished to avoid even this slight distortion of the relative sizes of the two halves.
This prohibition, quite obviously, applies in all times, in all places, and to both men and women. Violators are not liable to Malkut, as this prohibition falls under the category of “Lav Ha’nitan Le’tashlumin” – a violation which can be rectified by paying that which was received unlawfully.
The Rambam, in Hilchot Geneba (7:8), emphasizes that this prohibition forbids cheating anyone, whether a Jew or a gentile, and even an idol-worshipper. Furthermore, the Rambam adds, just as it is forbidden to cheat a Jew or gentile through the use of inaccurate weights and measures, it is similarly forbidden to cheat anyone – Jew or gentile – by intentionally miscalculating how much he owes. Tampering with the numbers in order to charge a client or customer a higher amount is strictly forbidden by Torah law.
Interestingly, the Sefer Ha’hinuch, in discussing this Misva, goes through a variety of mathematical principles, including concepts such as pi and the Pythagorean theorem. He writes that it is crucial for people involved in commerce to familiarize themselves with mathematics in order to be able to make accurate calculations and thus avoid inadvertent violations of this Torah prohibition.
Stories are told of great Sadikim who exercised particular caution when weighing and measuring in order to avoid inadvertent, slight mistakes to the detriment of the customer. When weighing or measuring merchandise, they would make a point of adding a little extra for the customer just in case the scale or measuring device was slightly inaccurate. The story is told of the patriarch of the famous Reichman family who, in his shop, would ensure to clean the dust off his scales each day, lest the weight of the dust slightly affect the weight of the merchandise he weighed for his customers. Some have speculated that it was in this merit that the family became exceedingly wealthy.
The Torah affords the highest priority to honesty and integrity, which is why this prohibition is treated with such exceptional severity. We are to be especially scrupulous and honest in all our financial dealings, and avoid taking even slightly more from people than we are rightfully entitled to take.