Why does Moshe not mention "Kevod Hashem" regarding the meat, like He will do regarding the Manna in Pasuk 16:7 ?
Rashi (to 16:7), Rashbam and Targum Yonasan 1 : Because, since, besides the fact that they had many animals, it was not correct to ask for meat, which is a luxury. Consequently, Hashem sent them meat (quails) at night, when it is unpleasant to collect it (it was not with a shining Countenance). 2
Ramban (citing Targum Onkelos) 3 : Whereas the quails, which Hashem blew in from the sea, were a natural phenomenon, the Manna was a wondrous miracle, akin to the creation of the world. 4 Hence Moshe told Yisrael that when they would see the quails fall that night, they would know Hashem had taken them out of Egypt and was sustaining them in the desert; whereas it was in the morning that they would witness the Kavod of Hashem; 5 they would know that there is no-one like Him, when He presents them with a new creation - the wondrous Manna.
Also see answer #2 and its note.
Bread, on the other hand, is a necessity, and it was perfectly legitimate to ask for it. Consequently, Hashem sent it in the day, graciously and with a shining Countenance. See the Ramban's objections to Rashi connecting this explanation with the words "Kevod Hashem."
See Ramban, DH 'v'Lachein.' By the same token, Targum Yonasan will explain the Pasuk like Rashi.
Ramban: As in Yeshayah 66:18, 19..
How would Yisrael know that night, that Hashem took them out of Egypt?
Ramban: Refer to 16:6:1:2 .
Seforno: This was actually a Tefilah - that when Hashem would provide them with food that night, it should be food that one eats at night; and the next morning, with food that one eats in the day - to initiate fixed eating times. 1
Seforno: Thereby taking them out of the Egyptian custom of eating at any time during the day, like animals; as the Gemara states, (Yoma 75b), 'Initially Yisrael were like chickens, which peck around the trash-heap, until Moshe came and introduced fixed meal-times. [Refer also to 16:7:1:3]. Included in the prayer was the request that the meat that they would receive that night would not suffice to satiate them , but that the bread in the morning would (refer to 16:6:1:1).