What are the connotations of the word "Anav"?
Why does the Torah insert it here?
Rashi (in Seifer ha'Pardes): Bearing in mind that "Anav" is missing a 'Yud' and can be read 'Anu', in answer to their criticism that, on his own initiative, Moshe had separated from his wife and had negated the Mitzvah of 'P'ru u'Revu', Hashem challenged them 'Anu bi!' Testify against Me, when did Moshe ever do anything against My wishes? 1
Ramban #1: To teach us that Hashem took Moshe's part precisely on account of his humility, since Moshe would never retaliate, even if he knew that someone had said something offensive about him.
Ramban #2 (citing Ibn Ezra): Moshe would never seek to be superior to anybody else, nor would he flaunt his superior position to anybody else