הכושית, from one of the tribes going back to Cham.

כי אשה כושית לקח, as reported in the biography of Moses (compare Yalkut Shimoni, edition by Heiman-Shiloni on Exodus page 34, glossary 18) According to that version, Moses ruled for 40 years as king over the land of Cush, took himself a woman as his queen but never slept with her, as reported there. Miriam and Aaron were never aware of the fact that Moses had not consummated that union. This is the plain meaning of our verse. If, as some believe, Miriam and Aaron spoke about Moses and Tzipporah, what need was there for the Torah to describe Moses’ wife as אשה כושית when everyone is well aware that Moses married Tzipporah the daughter of Yitro who was a Midianite, not a Cushite. Tzipporah could not have been described as Cushite seeing that the Cushites are descended from Cham, and the Midianites are descendents of the sons of Keturah, Avraham’s concubine, who bore 6 sons for him one of them being Midian. [Rash’bam’s argument is tenuous, for if Keturah was the same person as Hagar, according to most commentators, seeing that Hagar was an Egyptian, a woman descended from her could be described as Cushite, seeing that Mitzrayim, Egypt, was a descendant of Cham, also. Ed.]

'ויאמרו הרק אך במשה וגו, in addition to what they had already said concerning the Cushite woman to whom Moses was married, they also had another subject to criticise him for, namely that Moses could not boast about G’d communicating with him, seeing G’d did also speak to them.

בנו, using us as His medium.

פתאום, at the very moment when they were speaking about Moses. This was not a customary hour for G’d to communicate with them, but seeing G’d was upset about them on behalf of Moses, He wanted to pay him the honour of reacting immediately.

נביאכם, same as נבואתכם, “your prophecy.”

נאמן הוא, a permanent presence, belonging to the foundation at any time of the day. The word נאמן occurs in this sense of Isaiah 22,23 יתד במקום נאמן, “as a peg in a firm place.” It is something that is not apt to fall down.

אל נא תהי כמת, for reasons of your own honour and dignity do not allow yourself to become as if dead, for when someone who has been born from the same womb as your mother would be dead it is as if half of your own flesh is already dead.

אל נא תהי, do not become like a dead person The meaning of the words אל נא תהי as reflecting on the person addressed and not as the person who is the object of the conversation is also found in Proverbs 22,26, i.e.אל תהי בתוקעי כף, “do not be one of those who gives their hand, etc.” We also find this meaning in Proverbs 24,28 אל תהי עד חמס , “do not become a false witness.” [the author’s principal point is not to understand the word תהי as third person future feminine, but as second person, direct speech masculine. Ed.]