Psalms 136:9

12. “Happy shall he be that repayeth thee, as thou hast served us.” What repayment meaneth he? Herewith the Psalm closeth, “Happy, that taketh and dasheth thy little ones against the rock” ( ver. 9 ). Her he calleth unhappy, but him happy who payeth her as she hath served us. Do we ask, what reward? This is the repayment. For what hath that Babylon done to us? We have already sung in another Psalm, “The words of the wicked have prevailed against us.” For when we were born, the confusion of this world found us, and choked us while yet infants with the empty notions of divers errors. …

He, on the contrary, like one beside himself with fury, resists his doctor; he fights and struggles; he regards as a bitter foe one who only put forth his strength to drag him from the abyss of misbelief; and he does not indulge in this foolish anger only before chance hearers now and then; he has raised against himself a literary monument to record this blackness of his bile; and when in long years he got the requisite amount of leisure, he was travailling over his work during all that interval with mightier pangs than those of the largest and the bulkiest beasts; his threats of what was coming were dreadful, whilst he was still secretly moulding his conception: but when at last and with great difficulty he brought it to the light, it was a poor little abortion, quite prematurely born. …

6. But if even real virgins, when they have other failings, are not saved by their physical virginity, what shall become of those who have prostituted the members of Christ, and have changed the temple of the Holy Ghost into a brothel? Straightway shall they hear the words: “Come down and sit in the dust, O virgin daughter of Babylon, sit on the ground; there is no throne, O daughter of the Chaldæans: for thou shalt no more be called tender and delicate. …

But let us turn back to the passage first quoted, “If the spirit of the ruler rise up against thee, leave not thy place,” a sentence which is followed by these words: “for yielding pacifieth great offences.” The meaning is, that if the serpent finds his way into your thoughts you must “keep your heart with all diligence” and sing with David, “cleanse thou me from secret faults: keep back thy servant also from presumptuous sins,” and come not to “the great transgression” which is sin in act. Rather slay the allurements to vice while they are still only thoughts; and dash the little ones of the daughter of Babylon against the stones where the serpent can leave no trail. …

106. And David, pitying her, says: “O wretched daughter of Babylon.” Wretched indeed, as being the daughter of Babylon, when she ceased to be the daughter of Jerusalem. And yet he calls for a healer for her, and says: “Blessed is he who shall take thy little ones and dash them against the rock.” That is to say, shall dash all corrupt and filthy thoughts against Christ, Who by His fear and His rebuke will break down all motions against reason, so as, if any one is seized by an adulterous love, to extinguish the fire, that he may by his zeal put away the love of a harlot, and deny himself that he may gain Christ.