At Tara today in this fateful hour
I place all Heaven with its power,
And the sun with its brightness,
And the snow with its whiteness,
And the fire with all the strength it hath,
And the lightning with its rapid wrath,
And the winds with their swiftness along their path,
And the sea with its deepness,
And the rocks with their steepness,
And the earth with its starkness
All these I place,
By God's almighty help and grace,
Between myself and the powers of darkness.

This is called the Rune of St. Patrick, a variant on the much longer Lorica/Faidh Fiadha/Breastplate of St. Patrick. It was later used as a prayer/spell in Madeline L'Engle's A Swiftly Tilting Planet.