Why did Elazar not consult Moshe before teaching the Dinim of Hag'alas Keilim?
Eruvin, 73a: Indeed, based on the principle 'Kol ha'Moreh Halachah bi'Fenei Rabo, 1 Moridin oso mi'Gedulaso', it transpired that, because Elazar issued rulings in the presence of Moshe, Yeshoshua never required the services of Elazar.
Oznayim la'Torah: Except with regard to the division of the land, which was done by means of lots, which in turn, required the Urim ve'Tumim.
What prompted Elazar to issue a ruling in front of Moshe, and why did he not then defer to Yehoshua, who was Moshe's succcessor?
Oznayim la'Torah: Because he heard that after the war wih Midyan, Moshe would die, which he took to mean immediately - before he had the chance to teach Yisrael the Dinim - and this was borne out by the fact that Moshe forgot the Dinim. 1 He also thought that, since Yehoshua was obligated to consult him, he must be Yehoshua's senior, which explains why he did not defer to him to relate the Dinim of Hag'alah. 2
Oznayim la'Torah: As the Pasuk states in Koheles, 8:8 "ve'Ein Shilton be'Yom ha'Maves".
Oznayim la'Torah: Whereas in fact, a king is senior to a Kohen Gadol. In any event, it transpires that his punishment was perfectly appropriate - that Hashem issued Yehoshua his instructions directly, and he never needed to come on to Elazar.
Why did Elazar teach the Dinim of Hag'alas Keilim specifically to the troops?
Oznayim la'Torah: Because durng the war they had been permitted to eat the very same non-Kasher food that was absorbed in the Keilim that require Hechsher. He therefore needed to teach them that, although the Keilim in question did not require Tevilah during the course of the war, now they did, before they would be permitted to use them.
Why does the Torah write "ha'Ba'im la'Milchamah", and not 'ha'Ba'im min ha'Milchamah'?
Oznayim la'Torah: Because he was contrasting the Din now to what it was when they went to war. 1
Refer to 31:21:0.1:1.
What is "Zos Chukas ha'Torah" referring to?
Seforno: It refers to the Haza'ah with ashes of the Parah Adumah mentioned in the previous Pasuk.
What is the significance of the phrase "asher Tzivah Hashem es Moshe"?
Rashi: Elazar attributed the Halachos of Kashering Keilim to his Rebbi, Moshe (to stress that he did not hear it from Hashem but from Moshe).
Why did Moshe not teach the people the Dinim of Hag'alas Keilim?
Rashi: Because Moshe became angry, he erred and forgot them. 1
Rashi: In the same way as, on the eighth day of the Milu'im, he erred after getting angry with Elazar and Isamar (Vayikra 10:16), and after calling Yisrael 'rebels', he struck the rock (20:10, 11). See also Ba'al ha'Turim
