It is not the mouth that is the main thing to be looked at in prayer, but whether the heart is so full of affection and earnestness in prayer with God, that it is impossible to express their sense and desire; for then a man desires indeed, when his desires are so strong, many, and mighty, that all the words, tears, and groans that can come from the heart, cannot utter them.

The Works of that Eminent Servant of Christ, Mr. John Bunyan... (ed. 1769)