This short prayer, most likely originating in 10th century France, was used as a part of the knighting ritual. Although the ritual itself had many variations, this prayer always remained virtually unchanged. It was also included in the official ceremony of accepting a new member into the Teutonic Order. Although the prayer is not specifically mentioned in the Templar Rule its language is reflected in the preface (as noted by J. Frank Henderson in his article “Widows, Queens and Sword-bearers in Medieval Liturgical Prayers“). There is no reason to doubt that this (or very similar) prayer was used by the Knights Templar. Many coronation ceremonies include modified versions of this text.
Harken, we beseech Thee, O Lord, to our prayers, and deign to bless with the right hand of Thy Majesty this sword with which Thy servant wishes to be girded, that it may be a protection of churches, widows, orphans and all Thy servants against the cruelty of pagans, and may it be the fear, terror and dread of all evil-doers. In the name of Christ the Lord. Amen.