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.122
Letter to Arthur Greeves on December 29, 1935. "They Stand Together: The Letters of C. S. Lewis to Arthur Greeves (1914-1963)". Book by C. S. Lewis, p. 477, 1979.