Charles H. Spurgeon on Psalms 137:7

It may be observed that the Jews afterward acted the same part toward the Christian church which the Edomites had acted toward them, encouraging and stirring up the Gentiles to persecute and destroy it from off the face of the earth. And God "remembered" them for the Christians' sakes, as they prayed him to "remember Edom" for their sakes. Learn we hence, what a crime it is, for Christians to assist the common enemy, or call in the common enemy to assist them, against their brethren. —George Horne.