Charles Ellicott Commentary Exodus 16:13

"And it came to pass at even, that the quails came up, and covered the camp: and in the morning the dew lay round about the camp." — Exodus 16:13 (ASV)

At even the quails came up. —The common quail (Tetrao coturnix) is very abundant in the East, and regularly migrates from Syria and Arabia in the autumn of the year for the purpose of wintering in Central Africa, from where it returns in immense masses in the spring (Schubert: Reise, vol. ii., p. 361). Exhausted after a long flight over the Red Sea, the flocks drop to the ground as soon as they reach the coast, and it is then easy either to take the birds with the hand or to kill them with sticks.

Diodorus says that “the inhabitants of Arabia Petræa were accustomed to prepare long nets, and spread them near the coast for many furlongs, by which means they caught a great quantity of quails, which were in the habit of coming in from the sea” (ii. 60). The flesh of the quail is regarded as a delicacy throughout the East, though if too many are eaten it is said to be unwholesome.

The dew lay. —Literally, there was a deposit of dew. A heavy fall seems to be meant.