At the end of every radio broadcast, the inimitable J. Harold Smith would quickly pray, “Father, take this message and use it for Thy glory. Amen.”
I’m not sure what he prayed at the start of his sermons.
Sitting on the front pew throughout the first half of a worship service, what I pray goes something like this: “My Lord. Thank you for this privilege. Please anoint my lips and speak Thy word. Give me good recall for this message. Set a guard upon my mouth and keep watch over the door of my lips. May the words of my mouth and the meditations of my heart be acceptable to Thee, O Lord, my Rock and my Redeemer. And Father, use me to draw people to Jesus. For Thy sake. Amen.”
I may pray all or a part of that, but that’s my constant prayer.
A friend says he heard that in the moments before Charles Haddon Spurgeon rose to preach, he could be heard whispering repeatedly, “I believe in the Holy Spirit. I believe in the Holy Spirit. I believe in the Holy Spirit.”