Obeyed My voice.” The same was true of Yitzchak Avinu and Yaakov Avinu, who sat in the yeshivah and were privileged to study and observe the teachings of Torah she’b’al peh.
This then is the message HKB”H conveyed to the nations of the world who objected to the fact that Torah she’b’al peh was given exclusively to Yisrael: HKB”H silence them— "סתם פיהן"—because their mouths are not fit to study Torah—because they defile their mouths with prohibited speech and prohibited foods. He told them: “Bring Me your genealogical record . . . like My children bring.” Yisrael are the descendants of Avraham, Yitzchak, and Yaakov, who sanctified their mouths; Yisrael are privileged to inherit their neshamos from these holy Avos. Hence, they merited receiving the Torah she’b’al peh that the Avos were privileged to hear from the mouth of HKB”H.
In truth, however, HKB”H was conveying to them a more profound message. Yisrael, My children, are themselves a type of "ספר יוחסין". Since they are a “klaf ” for Torah she’b’al peh, their bodies are like a sefer Torah. You, the nations of the world, cannot make this same claim, because you are uncircumcised and are not vessels fit for kedushah.
In conclusion, this discussion teaches us a vital lesson. The true preparation for receiving the Torah on Chag HaShavuos—“zman matan toraseinu”—is to renew the covenant HKB”H entered into with Yisrael for the sake of Torah she’b’al peh. As explained, this is accomplished by sanctifying our mouths to be fit to serve as a “klaf” for Torah she’b’al peh. From the aspect of "סור מרע"—refraining from doing something wrong or negative—this entails limiting one’s speech, avoiding idle, meaningless chatter and, of course, refraining from lashon hara. From the aspect of "עשה טוב"—doing things that are good and positive—it is incumbent upon us to sanctify our mouths to be worthy of studying Torah she’b’al peh and davening with kavanah for Hashem to help us succeed in our pursuit of the chochmah of the Torah. In this merit, may we be privileged to renew our covenant with HKB”H on the auspiciously approaching Chag HaShavuos by receiving Torah she’b’chsav and Torah she’b’al peh on each one’s respective, kosher “klaf.”
