When they assembled together in this room after breakfast, the first they did was to light their pipes, and, while smoking, talk about the great things of the kingdom and spit all over the room, and as soon as the pipe was out of their mouths a large chew of tobacco would then be taken. Often when the Prophet entered the room to give the school instructions he would find himself in a cloud of tobacco smoke. This, and the complaints of his wife at having to clean so filthy a floor, made the Prophet think upon the matter, and he inquired of the Lord relating to the conduct of the Elders in using tobacco, and the revelation known as the Word of Wisdom was the result of his inquiry.
[Source: Journal of Discourses. Liverpool, England, 1853-86. 12:157-160; Deseret News. Also Deseret Evening News, Deseret News Weekly, Deseret News Semi- Weekly, and Deseret News Extra, Salt Lake City, in The Complete Discourses of Brigham Young, Ed. Richard S. Van Wagoner, Smith-Pettit Foundation, Salt Lake City (2009), http://bit.ly/BY-discourses]