Albert Barnes Commentary Psalms 78:27

"He rained flesh also upon them as the dust, And winged birds as the sand of the seas:" — Psalms 78:27 (ASV)

He rained flesh also upon them as dust - This refers to the flesh of quails (Numbers 11:31). The word “rained” means that they seemed to come upon them like a copious shower. The word “dust” denotes their great abundance.

And feathered fowls - The marginal note, following the Hebrew, reads “fowl of wing.” This is a poetic expression, designed to give beauty to the description by the image of their fluttering wings.

Like as the sand of the sea - This is an expression also designed to denote their great numbers (Genesis 22:17; Genesis 32:12; Genesis 41:49; Joshua 11:4; 1 Samuel 13:5; Revelation 20:8).