Tertullian

Who will ply the sword without practising the contraries to lenity and justice; that is, guile, and asperity, and injustice, proper (of course) to the business of battles? See we, then, whether that which has another action be not another sword,-that is, the Divine word of God, doubly sharpened with the two Testaments of the ancient law and the new law; sharpened by the equity of its own wisdom; rendering to each one according to his own action. Lawful , then, it was for the Christ of God to be precinct, in the Psalms, without warlike achievements, with the figurative sword of the word of God; to which sword is congruous the predicated "bloom," together with the "grace of the lips; "with which sword He was then "girt upon the thigh," in the eye of David, when He was announced as about to come to earth in obedience to God the Father's decree.