Khalid ibn al-Walid's letter to the Persian monarch Emperor Yazdegerd III, as quoted in John Clark Ridpath "History of the World, Volume IV (Book XII: The Mohammedan Ascendency, p. 463), 1910.
"Finding Safety in Counsel". Henry B. Eyring's address at the General Conference of the Church of Jesus Christ of Latter-day Saints, www.lds.org. April 1997.