George Whitefield (1771). “The Works of the Reverend George Whitefield, M.A...: Containing All His Sermons and Tracts which Have Been Already Published: with a Select Collection of Letters... Also, Some Other Pieces on Important Subjects, Never Before Printed; Prepared by Himself for the Press; to which is Prefixed, an Account of His Life, Compiled from His Orignial Papers and Letters”, p.47
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