Dr. Shades wrote:
Although the "flaming sword" image has become a meme, the wording was actually "drawn sword." So maybe a search for those words instead would turn up more hits.
I know of two quotes that call it a "flaming sword";
1. "He was commanded to obey it. He did not immediately comply. Then, according to Apostle George A. Smith, an angel with a flaming sword appeared to the Prophet Joseph and warned him that unless he obeyed it, he would be destroyed."
Journal History, L.D.S. Church Historian's Office, Salt Lake City, Oct. 9, 1869, containing copy of letter from Apostle George A. Smith to Joseph Smith, son of the Prophet Joseph Smith.
(Don Cecil Corbett, Mary Fielding Smith, Daughter of Britain: Portrait of Courage [Salt Lake City: Deseret Book Co., 1966], 154.)
2. "An angel with a flaming sword descended from the courts of glory and confronting the Prophet, commanded him in the name of the Lord to establish the principle so long concealed from the knowledge of the Saints and of the world. That principle was the law of celestial or plural marriage."
Life of Heber C. Kimball, by Orson F. Whitney, p. 321; Edition 1881; c. 1840.
Hasa Diga Eebowai