David Brainerd (1822). “Memoirs of the Rev. David Brainerd: Missionary to the Indians on the Borders of New-York, New-Jersey, and Pennsylvania: Chiefly Taken from His Own Diary”, p.125
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