Augustine of Hippo

"He shall defend you between His shoulders, and you shall hope under His wings" [Psalm 91:4]. He says this, that your protection may not be to you from yourself, that you may not imagine that you can defend yourself; He will defend you, to deliver you from the hunter's snare, and from an harsh word. …

Exposition on Psalm 91 ↗

Jerome

His truth shall surround you with a shield. Our shield is round, that is, it hedges us in on every side. Not only is it a shield, but it is also a wall. "Lord, as with a shield of your good will you have crowned us." Does someone crown with a shield? See what he says: Lord, as with a shield of your good will you have crowned us. What does he say? You will protect us, and make us conquer, and after the victory you will crown us. His truth shall surround you with a shield. …

Homily 20, on Psalm 90 ↗

Bonaventure

In this garden, there is much walking about, for if one is not happy to remain in the first, he goes to the second, and likewise with the others. And so man is compassed about with apples. Hence, in the Canticle: "Stay me up with flowers, compass me about with apples." And in the Psalm: "His truth shall compass thee with a shield." And so, as the intellect is ordained toward the affective dispositions, and faith is the way to charity, so also these enlightenments must pass over into the affective dispositions, in order that the …

Collations on the Hexaemeron, Collation 18 ↗