Ps. 78.44 (a previous reversal)

How he turned / their rivers / to blood
so they could not drink / from their streams. 

On first glance this verse simply recounts what is re-told in all of the various plague accounts of the exodus throughout the scriptures: the turning of the Nile to blood. However, when we say it thus we notice something important that clues us in to the psalmist’s particular use of the plague account. And that is this: there is no mention of the Nile but only “rivers and streams”. It seems minor until we look back in the psalm and notice this pair has been referred to already. In verse 16 God “splits the rocks” in the wilderness causing “streams to flow from a crag, water ran down like rivers.” As we saw in that section God first splits the waters of death (Red Sea) so that Israel can walk through dry, and then provides the water of life, like ‘streams and rivers’ in the wilderness. I believe this is supposed to resonate here, with the point being that whereas God provides Israel with ‘streams and rivers’ of life-giving water, he destroys the water of the Egyptians turning it into waters of death/blood. This point is further emphasized by the fact their failing to be able to drink the water. When he provided water to Israel they “drank as from a great deep” (vs. 15). Whereas God acts in prodigal abundance to his people/family, he reverses that in an act of counter-point to their enemies. This action by God will continue throughout the plagues. God provides ‘grain’ and then ‘bread’ to Israel. To Egypt, he destroys their ‘crops’ and then their ‘livestock’. In this way we come to see why the psalmist has organized the psalm in the way that he has—he is showing how centrally concerned God is for Israel, and how centrally disobedient Israel is to God by failing to remember and recognize this caring symmetry that God displays and enacts toward them.