Psalm 136, which begins "Give thanks to the LORD, for he is good, for his steadfast love endures forever," contains the phrase "for his steadfast love endures forever" as the second half of every single verse. I must confess: when I come across this psalm in my own devotions, I generally start to skip reading those second halves by about verse 5. Gerald, however, read the psalm in its entirety, including the refrain "for his steadfast love endures forever." He then drew our attention to some of the first halves of verses that are contrasted with that refrain in vv. 10-22.
"to him who struck down the firstborn of Egypt" (10)
"overthrew Pharaoh and his host in the Red Sea" (15)
"killed mighty kings" (18)
"for his steadfast love endures forever"?
It is a peculiar juxtaposition. Why does the psalmist give thanks for God's wrath against Egypt and the other nations? Because, as Gerald pointed out, God's wrath is directed against those who would harm Israel. And the Church, the worldwide people of God, should also give thanks today for God's wrath that is directed against that which would harm us.