At the conclusion of Parashat Behaalotekha, the Torah relates that Miriam and Aaron spoke about the Kushite woman whom Moses had married. What was the topic of their discussion? Why is Miriam mentioned first, and why was it specifically she who was afflicted with leprosy?

Why did the verse mention Miriam before Aaron in recording their conversation (see Numbers 12:1)? The verse teaches that Tzipora, Moses’ wife, went and told Miriam that Moses had separated from her, and Miriam went and told Aaron. The two of them rose and spoke against that righteous man. Because the two of them rose and spoke against the righteous man, punishment came upon them, as it is stated: “The wrath of the Lord was enflamed against them and departed” (12:9). What is the meaning of the term “and departed”? It teaches that the wrath of the Lord left Aaron and clung to Miriam, because Aaron was not the one who initiated the speech. But Miriam, who was the initiator of the speech, was immediately punished more severely than Aaron. Miriam said: God spoke to me, and I did not separate from my husband. Aaron said: And God spoke to me, and I did not separate from my wife. The same is true of our early ancestors, to whom God spoke, and yet they did not separate from their wives. But Moses, because he is arrogant, separated from his wife. Miriam and Aaron did not discuss the matter in Moses’ presence, [but] rather not in his presence [in order not to humiliate him]. They were not discussing it as a certainty but rather as a possibility; they were saying it was possible he was motivated by arrogance and possible he was not motivated by arrogance. [One can draw an (Avot deRabbi Natan, version A, chap. 9)