The psalmist’s prayer here against Edom and his cursing of Babylon in vv. 8-9 are according to the principle of good and evil (see note Psa. 37*1). According to the teaching of the New Testament, we should bless and not curse those who oppose us (Rom. 12:14), and we should pray for those who persecute us (Matt. 5:44).
cf. Isa. 35:10
Psalm 137 speaks of Israel’s remembering Zion and not forgetting Jerusalem (v. 5) in their captivity. After returning from their captivity, the captives had a sweet remembrance of the sorrowful experience of captivity. In spiritual experience, when we fall and are brought back by the Lord, in our reminiscence we taste the sweetness of the Lord’s mercy in restoring us.
