Origen, on Ps 136:8

“O daughter of Babylon, miserable: blessed shall he be who shall repay thee thy payment which thou hast paid us.”

“And in this way also the just give up to destruction all their enemies, which are their vices, so that they do not spare even the children, that is, the early beginnings and promptings of evil. In this sense also we understand the language of Psalm 137: "O daughter of Babylon, who is to be destroyed; happy shall he be that rewards you as you have served us; happy shall he be that takes and dashes your little ones against the stones." For "the little ones" of Babylon (which signifies confusion) are those troublesome sinful thoughts that arise in the soul, and one who subdues them by striking, as it were, their heads against the firm and solid strength of reason and truth, is the person who "dashes the little ones against the stones"; and he is therefore truly blessed. God may therefore have commanded people to destroy all their vices utterly, even at their birth, without having enjoined anything contrary to the teaching of Christ. And he may himself have destroyed before the eyes of those who were "Jews inwardly" all the offspring of evil as his enemies. And, in like manner, those who disobey the law and word of God may well be compared with his enemies led astray by sin; and they may well be said to suffer the same fate as they deserve who have proved traitors to the truth of God.”

Imported from an open dataset — not yet checked against the printed edition.