John Gills Exposition of the Bible Commentary - Psalms 78:44
And had turned their rivers into blood ,.... The river Nile and its seven streams; this was the first of the plagues of Egypt, Exodus 7:20 , and was a just retaliation for drowning the infants of the Israelites in their river, Exodus 1:22 , a like plague will be inflicted on spiritual Egypt, and with equal justice; see Revelation 11:8 , and their floods, that they could not drink ; the rivulets that flowed from the Nile, and every spring or confluence of water; or rather by these... read more
Matthew Henry's Complete Commentary - Psalms 78:40-72
The matter and scope of this paragraph are the same with the former, showing what great mercies God had bestowed upon Israel, how provoking they had been, what judgments he had brought upon them for their sins, and yet how, in judgment, he remembered mercy at last. Let not those that receive mercy from God be thereby emboldened to sin, for the mercies they receive will aggravate their sin and hasten the punishment of it; yet let not those that are under divine rebukes for sin be discouraged... read more