But even with words we ought at certain periods to make prayer to God, that by these signs of things we may keep ourselves in mind, and may know what progress we have made in such desire, and may stir up ourselves more actively to increase this desire, that after it have begun to wax warm, it may not be chilled and utterly frozen up by divers cares, without our continual care to keep it alive.
Words therefore are needful for us that we should be moved by them, that we should understand clearly what it is we ask, not that we should think that by them the Lord is either instructed or persuaded.
Reproduced in full. Translation: Oxford 1841 (Newman), public domain (Public domain).
Also cites: Epist. 130. 9