Psalms 78:27

Lastly, when both these things have been briefly touched, afterwards he is evidently following out the order of the narrative. "Because they believed not in God, nor hoped in His saving health." For when he had told why fire was lighted in Jacob, and anger went up upon Israel, that is to say, "because they believed not in God, nor hoped in His saving health:" immediately subjoining the evident blessings for which they were ungrateful, he saith, "and He commanded the clouds above, and opened the doors of Heaven." "And He rained upon them manna to eat, and gave them bread of Heaven." "Bread of angels man did eat: dainties He sent them in abundance." "He brought over the South Wind from Heaven, and in His virtue He led in the South West Wind." "And He rained upon them fleshes like dust, and winged fowls like the sand of the sea." "And they fell in the midst of their camp, around their tabernacles." "And they ate and were filled exceedingly; and their desire He brought to them: they were not deprived of their desire." Behold why He had delayed. But what He had delayed let us hear. "Yet the morsel was in their mouths, and the anger of God came down upon them." Behold what He had delayed. For before "He delayed:" and afterwards, "fire was lighted in Jacob and anger went up upon Israel." He had delayed therefore in order that He might first do what they had believed that He could not do, and then might bring upon them what they deserved to suffer. For if they placed their hope in God, not only would their desires of the flesh but also those of the spirit have been fulfilled. […]

He rained flesh also upon them as dust,....

He rained flesh also upon them as dust. First he rained bread and then flesh, when he might have rained fire and brimstone. The words indicate the speed, and the abundance of the descending quails. And feathered fowls like as the sand of the sea; there was no counting them. By a remarkable providence, if not by miracle, enormous numbers of migratory birds were caused to alight around the tents of the tribes. It was, however, a doubtful blessing, as easily acquired and super abounding riches generally are. The Lord save us from meat which is seasoned with divine wrath.

He rained flesh also upon them as dust - The flesh of quails, Num 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 - Margin, as in Hebrew, “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 - An expression also designed to denote their great numbers, Gen 22:17; Gen 32:12; Gen 41:49; Jos 11:4; 1Sa 13:5; Rev 20:8.