{h} Happy shall he be, that taketh and dasheth thy little ones against the stones.

(h) He alludes to Isaiah's prophecy in Isa 13:16 promising good success to Cyrus and Darius, whom ambition moved to fight against Babylon, but God used them as his rods to punish his enemies.

King James Translators' Notes

the stones: Heb. the rock

Matthew Henry's Concise Commentary

137:5-9 What we love, we love to think of. Those that rejoice in God, for his sake make Jerusalem their joy. They stedfastly resolved to keep up this affection. When suffering, we should recollect with godly sorrow our forfeited mercies, and our sins by which we lost them. If temporal advantages ever render a profession, the worst calamity has befallen him. Far be it from us to avenge ourselves; we will leave it to Him who has said, Vengeance is mine. Those that are glad at calamities, especially at the calamities of Jerusalem, shall not go unpunished. We cannot pray for promised success to the church of God without looking to, though we do not utter a prayer for, the ruin of her enemies. But let us call to mind to whose grace and finished salvation alone it is, that we have any hopes of being brought home to the heavenly Jerusalem.