Commentary for Numbers 12:12

אל נא תהי LET NOT our sister BE —

אל נא תהי כמת אשר בצאתו מרחם אמו ויאכל חצי בשרו, when a fetus is dead, having prematurely been aborted so that half its flesh looks as if it had already wasted away by the time it is expelled from its mother’s womb, even though it then appears in better condition than it was while still within its mother’s womb. When such a fetus leaves this world (mother’s womb) and enters the world of real life, perfect life, it still adds a negative dimension by being born, seeing that half of its flesh is consumed. Aaron asks Moses (whom he addresses here) not to leave his sister behind “dead” in the desert, whereas he will go on to the Holy Land, seeing that this would appear in retrospect as if he had left half of his own flesh (and blood) behind him in the desert.

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.