Regulation of Weights and Measures: A Torah Perspective

Weights and measures have always played a central role in the world of commerce. Because of their fundamental importance, we are able to trace a history spanning thousands of years of regulating their use. The Torah has much to say about this issue.

In modern times, when weights and measures are present in many homes, the laws of weights and measures apply not only to vendors and tradesmen, but can be relevant even to the ordinary householder.

In the present article we will discuss the Torah approach to regulation of weights and measures. Does the Torah prohibition concerning inaccurate measures apply to their use or even to their possession? What is the halachic status of weights and measures that are kept at home? Might even measured baby bottles be problematic? These questions, among others, are discussed below.

The Severity of Weights and Measures

In Parashas Ki Teitzei the Torah forbids the use of inaccurate measures with the following injunction: “You shall not have in your pouch a stone and another stone, large and small. You shall not have in your home a measure and another measure, large and small. A perfect and honest stone shall you have, a perfect and honest measure shall you have, so that your days shall be lengthened on the land that Hashem, Your God, gives you” (Devarim 25:13-15).

These prohibitions come in addition to the instructions in Vayikra: “You shall not commit a perversion in injustice, in measures of length, weight, or volume. You shall have correct scales, correct weights, correct dsy measures, and correct liquid measures – I am Hashem, your G-d, who brought you forth from the land of Egypt” (Vayikra 19:35-36).

It is all too easy to commit an offense in regard to weights and measures. A slight corruption of the measure will be virtually indiscernible to clients, will cause each individual consumer only a slight loss, but can in the long run lead to a considerable gain for the seller. The Torah thus addresses the issue of weights and measures with particular stringency and severity.

The Gemara (Bava Metzia 61a; Bava Basra 89b) presents a number of ways in which vendors deceive their customers by using imprecise weights and measures, such as one who soaks his weights in salt, or one who uses the same rope in the summer and the winter, in spite of the variations in length caused by changes in the weather. Deviations caused by salt or by weather conditions are of course slight, yet the full severity of the Torah prohibition applies.

In fact, Kessef HaKodashim (Choshen Mishpat 231:1) writes that the transgression of weights and measures is more severe than other means of deception because of the general reliance of the buyer on the honesty of the seller.

Obligation of Beis Din

Note that although the basic obligation of care in matters of weights and measures applies to each individual, there is also a special obligation on the community – and the Beis Din at its head – to regulate weights and measures so that people should not transgress.

The Shulchan Aruch (Choshen Mishpat 231:2) rules: “Beis Din is obligated to appoint inspectors who will go into stores to ensure the accuracy of weights and measures.”

Today, there is a legal obligation to have weights and measures approved by a universal standard. It is noteworthy that in many secular law frameworks the onus of ensuring accuracy of weights and measures falls on the national and local authorities, and the personal obligation of storekeepers is only to refrain from actively cheating the system.

This is in stark contrast to the personal obligation of halachah on each person using weights and measures.

Possession and Use

When a seller uses imprecise weights and measures, he is effectively stealing from the consumer – instead of giving him the requested (and paid for) 5 ounces of apples, he is giving him only 4.8 ounces. Why then is there a need for a special prohibition of inaccurate weights and measures? Is the regular prohibition against theft not sufficient?

We find an answer to this question is the Gemara (Bava Metzia 61b), which states that the Torah injunction is necessary since it forbids even the creation and subsequent possession of false measures, as it states, “You shall not commit a perversion in injustice, in measures of length, weight, or volume” (Vayikra 19:35).

Sefer HaChinuch (Mitzvah 602) articulates the prohibition as follows: “We are prohibited from keeping false weights and scales in our homes, even though we do not do business with them, lest they be a stumbling block before us. Therefore it is written (Devarim 25:13), ‘You shall not have in your pouch a stone and another stone, large and small,’ and ‘You shall not have in your home a measure and another measure, large and small.'”

This prohibition is likewise ruled by the Rambam (Laws of Theft 7:3): “One who keeps an imprecise measure or weight in his home or store transgresses a negative commandment.” The Shulchan Aruch (Choshen Mishpat 231:3) similarly records that possession alone is a transgression.

Two Sets of Scales

There are some stores in which one can find two sets of scales. One set, which is calibrated with great precision, is used at the cash desk for weighing items and determining their price. Other scales, whose measures are often less precise, are set aside for customer use, by which they determine approximately how much of a certain food or product they wish to buy.

Although the imprecise scales are not used for actual buying and selling, their presence in the store can involve a full prohibition. As we have seen, the prohibition applies not only to using the imprecise measures, but even to their possession.

Thus, we find a stringent warning issued in this spirit by the Ben Ish Chai, who writes that somebody in possession of imprecise measures transgresses a Torah prohibition each moment – even during ne’ilah of Yom Kippur!

However, where a legal standard of weights and measures applies, which is clearly marked on the scale by a certification, the possession of an uncertified scale will not involve a full prohibition (see below). If the law requires all commercial scales to be stamped, and the inaccurate scales do not bear the relevant stamp of approval, there is no chance of deception and the prohibition is not transgressed (Rambam and Shulchan Aruch; see below).

Giving a Little More

A person should be careful to weigh and measure generously so that the customer actually gets a little extra.

The Torah tells us (Devarim 25:15) “you shall have a perfect and just measure.” The Gemara understands the word “just” to mean at one’s own expense (Bava Basra 88b). By giving a little extra, one ensures that any inaccuracy or discrepancy in the measure will not cause the customer any actual loss.

Based on the Gemara, the Rambam rules that a person must tip the balance in favor of the customer, and even records the amount that should be added:

“What is the source that teaches us that one must tip the balance in favor of the purchaser when his purchase is being weighed for him? It states: “You shall have a perfect and just weight.” The Torah’s statements can be interpreted to mean: “Justify your balance from what you have and give it to him.”

“How much should the seller tip in the purchaser’s favor? With regard to liquid measure, one hundredth of the amount purchased. With regard to dry measure, one four-hundredth of the amount purchased.

“What is implied? If he sold him ten pounds of a liquid measure, he should give him one tenth of a pound extra. If he sold him twenty pounds of a dry measure, he should give him an extra twentieth of a pound. This ratio should be followed regardless of whether the amounts involved are great or small.”

Weights and Measures at Home

The Gemara (Bava Basra 89b) extends the prohibition of creating and possessing imprecise weights and measures beyond the grocer: “Rabbi Yehudah said in the name of Rav: It is forbidden to keep an imprecise measure in one’s house, even if it is made into a bedpan.”

Thus, even where the form of the weight or measure indicates its use for matters other than measurement, it remains forbidden to keep it at home, for fear that one might come to use it in business dealings. This extension of the prohibition is ruled by the Rambam (loc. cit.)

Based on the wording of the Rambam, who mentions that even a bedpan, which is calibrated so that it can be used as a measure, should not be kept out of fear that it will be used in business dealings, the Minchas Chinuch writes that the prohibition of possessing such an item is only rabbinic in nature. The Rabbis were concerned that the measure might be used in business dealings, and therefore prohibited even a home measure. Headds that this is the express opinion of the Rashbam (Bava Basra 89b).

However, the Even Haazel (Laws of Theft 7:3) points out that the wording of the Rambam, which states the prohibition of such a bedpan as part of the principle prohibition, implies that whatever the form of the inaccurate weight, a full Torah prohibition is transgressed.

This is also implied by the Rambam in his Book of Mitzvos (Negative Commandment 272), and by the Chinuch in our parashah, both of whom note the addition of this type of bedpan as part of the Torah prohibition. As to the rationale given for the prohibition, a concern lest possession lead to use of the measure for commerce, this rationale does not necessarily imply a rabbinic prohibition, but can be interpreted as the reason behind the Torah prohibition.

Based on the prohibition of keeping inaccurate weights and measures in one’s possession, there is room to question the status of everyday scales and measuring devices found in homes: bathroom scales, baby balances, food scales, tape measures, bottles with volume markings, and so on. Many of these devices are imprecise to begin with, and the inaccuracy often grows over time, such that it might be prohibited to keep them.

This, of course, is a difficult assertion. Can it be that all those who keep ordinary weights and measures in their possession transgress a Torah prohibition?

Baby Bottles and Tape Measures

Rabbi Shlomo Zalman Auerbach (Minchas Shlomo, vol. 3, no. 106), who was asked to address the status of a baby scale that somebody kept in his home, finds a possible reason for leniency in the ruling of the Gemara (Bava Basra 89b) and later authorities (see Rambam, Geneivah 8:4) concerning places in which the law requires all commercial scales to be stamped with a stamp of approval. Under such circumstances it is permitted to keep an inaccurate scale and measure, if it does not bear the stamp of approval.

Based on this, Rabbi Auerbach writes that the same principle can be applied to everyday weights and measures, whose very form bears testimony to their imprecision. Just as the absence of an official stamp ensures that inaccurate measures are not employed for commerce, so the obvious appearance of a measure as imprecise, is sufficient to permit its holding.

It is noteworthy that Rabbi Auerbach relies on his rationale specifically under the assumption that the prohibition of keeping inaccurate measures at home is rabbinic in nature, citing the above-mentioned opinion of Minchas Chinuch. As mentioned, the implication of the Rambam and others is that there is a full Torah prohibition. Yet, it is possible to apply his rationale even to a Torah prohibition, just as the Gemara does concerning an official stamp of approval.

In addition, Rabbi Auerbach points out that his rationale for permitting imprecise home scales might not apply to common tape measures. Unlike baby scales or a baby bottle, it is not easy to distinguish between precise or “professional” tape measures and those that are unprofessional and imprecise. Rabbi Auerbach therefore leaves the question of keeping an imprecise tape measure at home as tzarich iyun – a question requiring further scrutiny.

Occasional Use for Commerce

Another approach for finding leniency is brought up by the Kesef HaKodashim (Choshen Mishpat 231:3). Relating to measures used by householders to check quantities of produce, he writes that the prohibition of holding imprecise weights and measures applies only to those measures that might plausibly by used for commerce. Concerning weights and measures that are never used for commerce, the prohibition might not apply.

This line of reasoning can be applied to certain types of common weights and measures. A baby bottle is never used for commercial purposes; neither are bathroom scales. However, kitchen scales (especially electronic scales), might be plausibly used for buying and selling, such as in allocating the goods of a joint purchase among participants, or in small-scale sales between neighbors.

For such instruments the question of prohibited possession remains unanswered.

Defining Precision

An alternative reason that might justify keeping inaccurate measures at home is the relative definition of precision.

Precision, for purposes of halachah, is defined according to place and time. The precision required in one locale is not the same as that in another, and the precision of today is certainly different from that of a century ago. The obligation to ensure the precision of weights and measures depends on the degree of precision expected in the context of a particular sale (a different level of precision is used for gold than for apples) and a given place and time.

With this principle in mind, it stands to reason that the degree of precision required in a store is not the degree of precision required for sales in a non-commercial home environment. Weights and measures kept at home are not subject to government regulation, and a neighbor wishing to buy a kilo of flour realizes that the scale used to measure it will not be as precise as those used by stores and producers.

Therefore, it appears that weights and measures kept at home do not have to reach the degree of precision required of stores (of course with the exception of somebody who actually runs a home business). Rather, it is sufficient to ensure the degree of precision normal for home weights and measures.

However, if the precision of a home measure deviates from the normal degree of precision expected of a home environment – something that can happen over time if instruments are not calibrated regularly – keeping them in one’s possession might involve a prohibition – though it can be argued that cases of splitting with neighbors (and the like) are rare enough that keeping an inaccurate balance will not be a problem.

Certainly, somebody who does occasionally use a balance for purposes of splitting or sporadic selling to neighbors should therefore ensure that his scales and measures are maintained at a reasonable degree of accuracy.

Marking the Scales

On account of the stringency of the prohibition, and in view of the difficulties in finding a halachic solution, some Poskim have advised that home scales and measures be labeled, “INACCURATE”.

Shut Minchas Yitzcak (Vol. 10, no. 149) equates marking as inaccurate with the above leniency of a place in which commercial weights and measures bear a standard stamp.

He adds that whereas everybody knows that a measure without an official stamp is not guaranteed to be accurate, in the case of a marking somebody in a rush might miss the “INACCURATE” label. Yet, if the word is clearly marked it stands to reason that this indication is sufficient to avert any possible prohibition – in particular given the additional reasons for leniency noted above.

Summary

• It is forbidden for a storeowner to keep an inaccurate balance in his store, even if the balance is not used for sales.
• It is likewise forbidden to keep inaccurate weights and measures at home, if their external appearance does not imply their imprecision.
• Poskim permit keeping possession of weights and measures whose appearance clearly indicates their being imprecise – such as marked baby bottles, bathroom scales, and the like.
• For home weights and measures whose appearance does not indicate inaccuracy, such as electronic kitchen scales, tape measures, and so on, one should ensure that the measure is as accurate as possible – especially if the instrument is occasionally used for purposes of dividing goods with neighbors or for one-time sales. If the instrument becomes inaccurate, it is best to mark the instrument  “INACCURATE”.
• Where government regulation of measures applies, and measures must be marked with a stamp of approval, there is general room for leniency in a professional environment for keeping inaccurate scales that do not have a stamp of approval.