Exodus 8:31
29 Moses said, “I am going to go out from you and pray to the Lord, and the swarms of flies will go away from Pharaoh, from his servants, and from his people tomorrow. Only do not let Pharaoh deal falsely again by not releasing the people to sacrifice to the Lord.” 30 So Moses went out from Pharaoh and prayed to the Lord, 31 and the Lord did as Moses asked—he removed the swarms of flies from Pharaoh, from his servants, and from his people. Not one remained! 32 But Pharaoh hardened his heart this time also and did not release the people.
Wisdom of Solomon 16:18
16 for the ungodly, refusing to know you, were flogged by the strength of your arm, pursued by unusual rains and hail and relentless storms, and utterly consumed by fire. 17 For—most incredible of all—in water, which quenches all things, the fire had still greater effect, for the universe defends the righteous. 18 At one time the flame was restrained, so that it might not consume the creatures sent against the ungodly, but that seeing this they might know that they were being pursued by the judgment of God; 19 and at another time even in the midst of water it burned more intensely than fire, to destroy the crops of the unrighteous land. 20 Instead of these things you gave your people food of angels, and without their toil you supplied them from heaven with bread ready to eat, providing every pleasure and suited to every taste.
Notes and References
"... The plague of the flies comes along with that of the gnats or mosquitoes. They seemingly carry diseases dangerous to human beings and thus extend the cycle of miseries. Unlike the previous plagues, this one is predicted in advance to occur on a precise day, in order to show the Pharaoh that it comes from the Lord (8:23). It affects the Egyptians but not the population of the Hebrews living in the region of Goshen (8:22), which is identified in Genesis 45:10 as the Hebrews’ place of settlement in Egypt. It may refer to Wadi Tumilat, a region that was often inhabited by foreign tribes during the New Kingdom (between 1500 and 1000 BC). Wisdom of Solomon 16 draws up a contrast here between the plagues of the flies and locusts and the serpents that afflicted the Hebrews in the desert (Numbers 21:6; Deuteronomy 32:33). While both peoples experienced chastisements from the Lord, one of them remained impenitent, and the other found healing by recourse to the mercy of God. Behind the deprivations of human existence, even those that are very significant, recourse to the presence of God and the hidden face of divine mercy is always possible. With the grace of God, every human trial can become an occasion for deeper faith and spiritual intimacy with God ..."
White, Thomas Joseph Brazos Theological Commentary on the Bible: Exodus (pp. 119-120) Brazos Press, 2016