St. Francis of Assise wrote a magnificent prayer illustrating the total awe and respect that he had for the Holy Eucharist and shared it with his Franciscan brothers who have preserved it and passed it down through time.  It is from A Letter to the Entire Order (1225-1226) published in Francis of Assisi: Early Documents, Volume I by New City Press, New York.

Let every one be struck with fear,
let the whole world tremble,
and let the heavens exult
when Christ the Son of the Living God,
is present on the altar in the hands of a priest!
O wonderful loftiness and stupendous dignity!
O sublime humility!
O humble sublimity!
The Lord of the universe,
God and the Son of God,
so humbles Himself
that for our salvation
He hides Himself
under an ordinary piece of bread!
Brothers, look at the humility of God,
and pour out your hearts before him!
Humble yourselves
that you may be exalted by Him!
Hold back nothing of yourselves for yourselves,
that He who gives Himself totally to you
May receive you totally!

Amen.