The imagery in the first lines is from Psalm 121. It brings to mind scenes of war movies or old Westerns, when the besieged protagonist is crouched behind some scraggly bush, quickly running out of ammo, and suddenly from the hill on the horizon, rank on rank of replacements come galloping in.
The “Under thy protection” prayer to Our Lady is the earliest known Marian prayer, dating as far back as only 200 years after Christ. Just think of the generations of Christians who have had these words on their lips in times of trouble.
We can also invoke the angels in times of physical danger. Scripture tells us of how successfully they are able to ward off threats. Just think of what Daniel reported after a night in the lions’ den: “My God sent his angel and closed the lions’ mouths so that they have not hurt me” (6:23). This prayer draws from the promise of the angels in Psalm 91.
Finally, the line about entrusting our souls to God’s mercy comes from Pope Emeritus Benedict XVI in his “Last Testament.”
Adapted from a Prayer for a Tornado Shelter.