Psalms 137:7 - Joseph Benson’s Commentary on the Old and New Testaments

Remember, O Lord, the children of Edom Their constant and inveterate enemies, who had no regard either to consanguinity or humanity, but, instead of pitying Jerusalem, as became kind neighbours and relations, were glad to see the day of its desolations; and encouraged their destroyers with their acclamations, saying, Rase it, rase it, &c. Hebrew, ערו ערו, make it bare, empty it, or lay it flat, even to the foundation thereof, or the ground on which it stands. Edom is charged with this unnatural behaviour, and threatened for it by God himself in the prophecy of Obadiah, Obadiah 1:10, and for it God's judgments came upon them, as it was here foretold they should do.