Musar к Бамидбар 12:11

And they also expounded (in Vayikra Rabbah 16) the verse (Koheleth 5:5): "Do not allow your mouth to cause sin to your flesh" — do not speak lashon hara with your mouth to punish all of your flesh with this sin. The Rabbis applied this verse to Miriam: "Do not allow your mouth" — you, Miriam, as it is written (Numbers 12:10): "And, behold, Miriam was leprous, [white] as snow." (Koheleth, Ibid.): "that it was an error" — as it is written (Numbers 12:11): "wherein we [(Aaron and Miriam)] have erred and wherein we have sinned." (Koheleth, Ibid.): "Why should G-d be angry at your voice?" — at the lashon hara you have spoken against Moses, as it is written (Numbers 12:9): "and the anger of the L-rd burned against them, and He departed." (Koheleth, Ibid.): "and [He shall] destroy the work of your hands." R. Yochanan said: "With her mouth she sinned, and all her limbs were smitten, as it is written (Numbers 12:10): 'And the cloud departed from the tent, and, behold, Miriam was leprous, [white] as snow.' This is the intent of: "Do not allow your mouth to cause sin to [destroy] your flesh" … (Mishlei 21:33): 'He who guards his mouth and his tongue guards his soul from troubles.'"

בחר לנו אנשים. Rashi sees in the word לנו proof that Moses equated Joshua with himself in this task. The Rabbis deduced from this a rule that a teacher should always be as concerned with the honour of his student as with his own. The honour of someone of equal status to oneself, however, should be placed on a par with the honour of one's teacher. The source for this is found in Numbers 12,11 where Aaron, Moses' older brother, addresses him with the words: בי אדוני, "Please my lord!" The honour of one's teacher should be treated as equivalent to the honour of G–d Himself. We derive this from Numbers 11,28 where Joshua pleads with Moses to kill Eldod and Meydod for prophesying the death of Moses. The words used are: אדוני משה כלאם. Joshua felt that insubordination against his teacher Moses deserved the same penalty as insubordination against G–d Himself. We can now understand why we are taught in Avot 4,1: "Who is truly honoured? He who honours G–d's creatures."