Impone Domine, capiti meo galeam salutis, ad expugnandos diabolicos incursus.
Place upon my head, O Lord, the helmet of salvation, for conquering diabolical assaults.
The idea of the syntax here is not that we, of ourselves, have the power to beat down whatever future diabolical assaults there may be during the ultimate religious battle during the Holy Sacrifice of the Mass, but that, knowing that we cannot do that, we humbly ask the Lord that He Himself cover us with the grace of salvation, which, of itself, conquers the assaults of the Evil One.
We are reminded of Saint Paul’s letter to the Ephesians (6,12-17 of the old NAB):
For our struggle is not with flesh and blood but with the principalities, with the powers, with the world rulers of this present darkness, with the evil spirits in the heavens. Therefore, put on the armor of God, that you may be able to resist on the evil day and, having done everything, to hold your ground. So stand fast with your loins girded in truth, clothed with righteousness as a breastplate, and your feet shod in readiness for the gospel of peace. In all circumstances, hold faith as a shield, to quench all (the) flaming arrows of the evil one. And take the helmet of salvation and the sword of the Spirit, which is the word of God.
A helmet, obviously, protects the head, with a spiritual helmet fending off untoward assaults of a spiritual nature. Such spiritual assaults are usually mind games the devil puts before us, about which Saint Paul instructs and reprimands us: “For our struggle is not with flesh and blood but with the [...] evil spirits in the heavens.”
The temptation is for us to dumb-down the battle to that of flesh and blood, a sheer idiocy on our part, laying ourselves wide open to diabolical assaults, having us be filled with rancor and discord and, to justify ourselves, disobedience to the faith. And one can offer Holy Mass with that kind of attitude, which is horrific, but it happens with so very many of us.
Saint Paul here speaks of obedience to the truth of the faith, which frees one to be an apostle of the Gospel, to be the edge of that sword of the Spirit, which is the word of God. In one’s preaching, with all clarity of mind and agility of spirit, one helps others to understand that we do not battle with flesh and blood, but with the evil spirits, and that we are to pray and help each other to be the best of friends with our Lord Jesus, to be His humble servants.
Remember that original sin came about because of the deception, the mind games of Satan, who tried to get flesh and blood to battle with flesh and blood, with rancor and discord all around. This prayer is an in-your-face mockery of Satan’s assault on Adam, and therefore on mankind, from the very beginning. This prayer points to the promised Redeemer of Genesis 3,15. Having taken the initiative to crush the head of Satan and be crushed – what is happening at the Holy Sacrifice of the Mass we prepare to offer with this prayer – only our Lord Jesus can provide us with the helmet of salvation so as to repel the deceit, the mind games, of the Evil One.
When our Lord Himself was especially assaulted by the mind games of the devil during those forty days in the desert after He made the waters of baptism holy by His own Baptism, the temptation was about things of flesh and blood, about egoism and rancor and discord. The response of the Lord to each temptation was about His bond of union in all charity with His, with our heavenly Father. Love conquers all mind games. The helmut of salvation means to have a mind and a judgment of things based on love of God and love of neighbor with one and the same act of love.
“Place upon my head, O Lord, the helmet of salvation…” Yes! A prayer we would surely want to say before offering the Holy Sacrifice.