He turned their rivers to blood, so that they could not drink of their streams.
PSALM 78 To comprehend many things within small compass, it is to be observed, that in this psalm there are two leading topics. On the one hand, it is declared how God adopted for himself a Church from the posterity of Abraham, how tenderly and graciously he cherished it, how wonderfully he brought it out of Egypt, and how varied were the blessings which he bestowed upon it.
Commenting on Psalm 78:1-72
And had turned their rivers into blood. The waters had been made the means of the destruction of Israel's newborn infants, and now they do as it were betray the crime—they blush for it, they avenge it on the murderers.
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.
Commenting on Psalm 78:40-72