True to Your Word
Q. Where in the Torah does it say you have to keep your word?
A. I field a lot of ethical questions. Sometimes I tell people they have an ethical obligation to say something because it's true, or to do something because they promised to. Usually people are satisfied with this answer. It makes intuitive sense to them that you shouldn't try to get credit for something you didn't do by lying. But some people need further convincing. In fact, more than one person has in effect asked me, "Where in the Torah does it say you're not allowed to lie?"
From an ethical point of view, this question is completely upside down. It assumes that the obligation to keep our word, if any, is a consequence of our obligation to keep the Torah. In fact, the order of causation is exactly the opposite: Our obligation to uphold the Torah is a consequence of our solemn obligation to keep our word.
Jewish tradition emphasizes that the obligation of the Jewish people to keep God's Torah stems from our free acceptance of the covenant offered by Him. Before receiving the Torah on Mount Sinai, God offered the Jewish people a deal: "If you will heed My voice, and keep My covenant, then you will be My treasure among the nations, for all the land is Mine. And you will be to Me a nation of priests, and a holy people." (Exodus 19:5-6.) Afterwards, Moses brought this offer to the people. "And all the people answered and said, Everything that God has spoken, we will fulfill." (Exodus 19:8.) Only when Moses relayed this reply to the Almighty did He begin to arrange the unique mass revelation at Sinai, and subsequently to give the Ten Commandments and then the rest of the Torah.
Many Midrashim also indicate that it was this free acceptance which obligates us. One Midrash learns that the Torah was offered not only to the Jewish people, but also to other nations, who declined it. (1) Another suggests that because the acceptance of the covenant on Mount Sinai had an element of compulsion, it was not really binding; the Torah become completely obligatory only when Jews of a later generation made a renewed acceptance. (2)
Only a commitment which is freely entered into can totally obligate a person, or a nation. We see this from the evolution of humanity. The first commandment given to mankind, to Adam and Eve, was to not eat of the Tree of Knowledge of good and evil. This order was imposed unilaterally; the outcome was that its observance lasted no more than a few hours.
Afterwards, God gave many commandments to Noah and his offspring. These commandments were dictated by God, but there also was an element of voluntary acceptance, as we find that the Torah calls this a "covenant" or agreement. (Genesis 9:9.) This agreement was more durable, and to this day the Noahide commandments constitute a viable foundation for human civilization. But our Sages tell us that ultimately many nations forsook this covenant as well. (3) Others observe the conditions, but fail to acknowledge their covenantal nature.
By contrast, the covenant at Sinai was accepted whole-heartedly by the Jewish people, and we continue to hold fast to it thousands of years later.
The sanctity of our voluntary commitments is not a consequence of the yoke of Torah, it is the very basis of this yoke. We are only worthy of being commanded because of our basic human trait of commitment to our promises. We need to remember this in our everyday lives, and recall that our ability to make commitments and our responsibility to keep them is the foundation of our humanity.
SOURCES: (1) Rashi commentary on Deuteronomy 33:2 (2) Babylonian Talmud Shabbat 88a (3) Babylonian Talmud Avodah Zarah 2b