Here's some information on the little prayer that I learned years ago...
This delightful old English prayer said by children and their parents at bedtime has long ago been shortened to only its last verse. There is more (as I was taught):
Matthew, Mark, Luke and John,
Bless the bed that I lie on.
The are four corners to my bed,
Four angels round my head
One to watch, and one to pray,
And two to bear my soul away.
Now I lay me down to sleep
I pray the Lord my soul to keep.
If I should die before I wake,
I pray the Lord my soul to take.
I went through a whole number of prayers yesterday. From parts of the Rosary, the Lord's Prayer, the 23rd Psalm, and finally this little prayer. I really couldn't concentrate on anything else...so these prayers that I have known for years were easy to say to keep me quiet and calm. It worked for me for 45 min. yesterday. Now, I'm finished and it's in my doctor's hands and God's.