Rashi (Vayikra 25:1) and Ramban (Vayikra 7:38) both quote the teaching of the Toras Kohanim that Hashem taught the Torah to Moshe in its entirety three times: once on Har Sinai, then again when the Mishkan was erected, and a third time at Arvos Moav, just as Bnei Yisrael were about to enter Eretz Yisrael. This opinion is shared by Rabi Akiva (Chagigah 6b). Rabi Yishmael disagrees, however, and maintains that Moshe was taught only general topics on Har Sinai, while the details of the halachos were given later, when the Mishkan was erected.

According to the opinion of the Toras Kohanim and Rabi Akiva, it would seem that Moshe should have had the answer to every halachic question brought to him following Matan Torah. Even according to Rabi Yishmael, we would expect this to be the case from the time that the Mishkan was built and onward. Yet there are seven distinct cases reported in the Gemara, the Midrash, and other sources in which Moshe Rabbeinu was unaware of a halachah even though the Torah had already been given. One of these cases, in fact, took place no less than two weeks after Bnei Yisrael received the Torah. This gives rise to a glaring question: if Moshe Rabbeinu received the Torah in its entirety at Har Sinai, how can we explain the fact that he was unable to provide rulings in these seven instances?

Forgetfulness: A By-Product of Anger

The question can be resolved relatively easily with regard to three of these cases. In each of these instances, Moshe’s inability to issue a halachic ruling was preceded by a display of anger, which can account for his inability to determine the halachah.

The first two episodes are cited in Sifri (#157, quoted by Rashi in Bamidbar 31:21). The Torah (Bamidbar 31:14) relates that when Bnei Yisrael returned with the spoils of war from defeating the Midyanim, Moshe became angry with them for preserving the lives of the women who had caused the Jewish men to sin (see Rashi, ibid. 16), and had thereby brought about a plague that caused 24,000 Jewish deaths. The Torah goes on to relate that it was Elazar, not Moshe, who taught Bnei Yisrael how to purify the nonkosher vessels that they had captured. Sifri explains that Moshe had in fact learned this halachah earlier, but he was unable to recall it as a result of his anger.