At work I have been moved to a different building, a different team, and am doing something different, which takes some getting used to, so I haven’t had time to write much here. Anyway… a quick idea from R’ Meir Shapiro of Lublin:
Moshe Rabeinu was very reluctant to accept the mission of serving as the redeemer of Bnei Yisrael and he tried to use his speech impediment as an excuse. Hashem responded that He, Hashem, is the one who grants the power of speech; surely if He wishes Moshe to speak to Pharaoh, Moshe will have the ability to do so. “Mi sam peh l’adam…. ?!” But Moshe didn’t give up so easily. Moshe again argued, “Shlach na b’yad tislach,” that Aharon should be sent instead. Hashem at this point got angry and answered that Moshe need not worry that Aharon will feel slighted, as “Aharon achicha halevi,” is headed out to happily greet Moshe.
Chazal (cited by Rashi) see in this response not only an answer, but a punishment to Moshe as well. Why does the Torah mention Aharon being a levi specifically in this context? Chazal explain that Moshe himself was going to be given the future honor of serving as kohen gadol, while Aharon would be a levi. However, because of his argument here, Moshe was denied that privilege. Aharon the levi would become kohen gadol, and Moshe would serve as levi instead.
It’s very hard to understand why Moshe continued to argue with Hashem after he heard Hashem’s answer of, “Mi sam peh…” Why was he not satisfied with that answer? And what are we to make of his demotion from potentially being kohen gadol to instead serving as levi? All of the punishments in the Torah are “midah k’neged midah” – the punishment is a precise inverse of the crime. How is Moshe being made a levi a fitting punishment for his continuing to argue?
The Lubliner Rav explained that it was precisely because Moshe understood full well Hashem’s message of, “Mi sam peh…,” that he continued to argue. Moshe said, “If you Hashem are the one opening my mouth and putting words in it, hayitachein, is it possible that I should use such a holy mouth to speak to a person like Pharoah?!” What a waste, an abuse, a degradation, of this awesome power of speech!
This is why Moshe became a levi and not a kohen. What was the job of the levi’im? To sing shirah in the Mikdash. Who is more fitting for such a role than the person who appreciates the gift of speech in its fullest sense? Moshe’s “punishment” was indeed, a perfect match for the “crime” of his argument.