Praevaluitque David adversum Philisthaeum in funda et lapide, percussumque Philisthaeum interfecit. Cumque gladium non haberet in manu David, cucurrit, et stetit super Philisthaeum, et tulit gladium eius, et eduxit eum de vagina sua: et interfecit eum, praeciditque caput eius. (From the Second-Third Lessons for Tuesday in the IV Week after the Pentecost Octave, Roman Breviary - I Kings/I Samuel xvii, 50-51: "And David prevailed over the Philistine, with a sling and a stone, and he struck, and slew the Philistine. And as David had no sword in his hand, he ran, and stood over the Philistine, and took his sword, and drew it out of the sheath, and slew him, and cut off his head. And the Philistines seeing that their champion was dead, fled away.")
[David] laid aside His armour, He took five stones: He laid aside, as we have said, the burdensome armour: He laid aside, that is, the rites of the Law, those rites of the Law which are not laid on the Gentiles, which we do not observe. For ye remember how much we read in the old Law, which we do not observe, yet understand to have been sent before, and set forth to signify somewhat; not that we cast away the Law of God, bul that we celebrate not the rites of promise, now that the promise is fulfilled. For what they promised has come. For the grace of the new covenant which was veiled under the Law, is unveiled in the Gospel....Armed ... with grace, and so not trusting in himself, — but in his Lord, he went forth against the proud Goliath, who vaunted himself, trusted in himself. He took one stone, he cast it, he smote his enemy in the forehead ... . He put five stones in his scrip, he hurled but one. The five Books were chosen, but unity conquered. For the fulfilment of the Law, as we mentioned a little above, is love: and the Apostle saith, 'Forbearing one another in love; endeavouring to keep unity of spirit in the bond of peace'. Then, having smitten and overthrown him, he took the enemy's sword, and with it cut off his head. This our David [i. e. Christ] also did, He overthrew the devil with his own weapons: and when his great ones, whom he had in his power, by means of whom he slew other souls, believe, they turn their tongues against the devil, and so Goliath's head is cut off with his own sword.
Enarratio in Psalmum CXLIII[Personal recess for several days.]