Numbers 12:2

Hath the Lord indeed spoken only by Moses? — There is probably a reference in these words to the facts related in Exodus 4:10, where Moses speaks of his own slowness of speech (Numbers 12:10), and where it is said of Aaron, “And he shall be thy spokesman unto the people” (Numbers 12:16). Miriam also is spoken of in Exodus 15:20 as “the prophetess.” “Such is the depravity of human nature,” writes Calvin, “that they not only abuse the gifts of God towards the brother whom they despise, but by an ungodly and sacrilegious glorification extol the gifts themselves in such a manner as to hide the Author of the gifts.”