Charles Haddon Spurgeon (1988). “Spurgeon at His Best: Over 2200 Striking Quotations from the World's Most Exhaustive and Widely-read Sermon Series”, Baker Publishing Group
William Law (1749). “I. The spirit of prayer; or, the soul rising out of the vanity of time, into the riches of eternity. In two parts ; 7,II. The way to divine knowledge; being several dialogues between Humanus, Academicus, Rusticus, and Theophilus”, p.24