How would they see the Kavod of Hashem in the morning?
Rashi and Rashbam: It means that Hashem would provide them with bread in the morning, with a shining countenance. 1
Ramban (citing also Targum Onkelos): Refer to 16:6:1:2.
What did Moshe mean when he said (About himself and Aharon) "v'Nachnu Mah"?
Rashi, Ramban and Targum Yonasan: He meant "Of what significance are we." 1
Rashi (to Devarim 7:7): This typifies Yisrael, who always belittle themselves. 2
Chulin 89a #1: 'I have a strong desire for you,' says Hashem, 'because even when I shower you with greatness, you make yourselves small. I bestowed greatness upon Moshe and Aharon .... 3
Chulin 89a #2 Based on a Gezerah Shavah "Nachnu Mah," "Toleh Eretz Al B'li-Mah" (Iyov 26:7), the entire world exists only because of Moshe and Aharon. 4
Chulin 89a #3: What the Torah says about Moshe and Aharon, "v'Nachnu Mah;" is greater than what it says about Avraham, "v'Anochi Afar va'Efer." 5
Ramban: So how could Yisrael complain about them when everything that happens is orchestrated by Hashem, and they were totally incapable. This is the meaning of the word "Mah" - as in Tehilim 8:5, and in Yeshayah 2:22. Rashi (commenting on the Pasuk, "for you are the smallest of all the nations" - Devarim 7:7) - This is the mark of Tzadikim, who negate themselves before Hashem, like Avraham, who declared "I am dust and ashes" (Bereishis 18:27), and like Moshe and Aharon, who declared "and what are we!"
See note in answer #1. See also Torah Temimah, note 11.
See note in answer #1.
See Torah Temimah, note 12.
See Torah Temimah, note 13.