"St. Patrick's Breastplate" Protective Prayer:
Celtic monks used it to start their day.The hymn was several stanzas long, and the last two stanzas were especially memorable and moving:

Christ be with me, Christ within me,Christ behind me, Christ before me,Christ beside me, Christ to win me,Christ to comfort and restore me.
Christ beneath me, Christ above me,Christ in quiet, Christ in danger,Christ in hearts of all that love me,Christ in mouth of friend and stranger.
I bind unto myself the Name,The strong Name of the Trinity;By invocation of the same.The Three in One, and One in Three,
Of Whom all nature hath creation,Eternal Father, Spirit, Word:Praise to the Lord of my salvation,Salvation is of Christ the Lord.