John Gill Bible Commentary

Happy shall he be that taketh and dasheth thy little ones against the stones. That takes the infants from their mothers' breasts, or out of their arms, and dashes out their brains against a "rock", as the word (k) signifies; which, though it may seem a piece of cruelty, was but a just retaliation; the Babylonians having done the same to the Jewish children, and is foretold elsewhere should be done to theirs, Isa 13:16. Nor is this desired from a spirit of revenge, but for the glory of divine justice, and that such a generation of cruel creatures might be rooted out of the earth; see Rev 2:2. Some allegorically understand this of crushing and mortifying the first motions of sin in the heart; but such a sense seems to have no place here. (k) "ad petram", V. L. Pagninus, Montanus, &c. "ad repem", Cocceius. Next: Psalms Chapter 138