The Cloud of Unknowing, ed. by Evelyn Underhill, , at sacred-texts.com
Here Beginneth the Prayer on the Prologue
GOD, unto whom all hearts be open, and unto whom all will speaketh, and unto whom no privy thing is hid. I beseech Thee so for to cleanse the intent of mine heart with the unspeakable gift of Thy grace, that I may perfectly love Thee, and worthily praise Thee. Amen.