“A perfect and just weight shalt thou have; a perfect and just measure shalt thou have; that thy days may be long upon the land which the L-RD thy G-d giveth thee.”
– Deuteronomy 25:15, JPS 1917 Tanach
The Torah commands us that we should have perfect and honest weights and measures (see above-mentioned verse, Deuteronomy 25:16). Rashi explains, that it is forbidden to use a large weight when buying, in order to get a grater quantity; and, a small weight for the sake of selling, in order to lose less. Sforno states clearly, “It’s forbidden for a Jew to own inaccurate weights and measures. Otherwise, the seller would be misled to give more than the buyer paid for; and, the buyer would receive less than actually paid for. G-d forbid.
In both of these cases, it is considered dishonest to deceive the seller or the buyer. Rather, H’Shem would have us be honest in all of our means of business. So, this commandment may be applied in other ways, to modern-day application as well. H’Shem would also like us to have the quality of honesty in our own lives as well that is perfect. Honesty should be an integral part of our character, so that we may live a life according to the ways, articulated by G-d’s words.
As Rosh HaShannah approaches, when we begin to weigh our lives in the balance, during the month of Elul, determining for ourselves by way of “examining our conscience,” whether we have been living according to H’Shem’s standard (the Torah), we will benefit from the endeavor when we do not cheat ourselves. For example, it may be too easy to weigh our good deeds against our faults, tipping the scale to the positive by ignoring some of the negative aspects of ourselves. Yet, on the other hand, if we focus too much upon the negative in regard to ourselves, we may risk bringing our emotional levels down too low. Rather, we should seek an honest account and balance the scale, with the help of H’Shem.
The Tree of Life 