George A. Smith teaches that he knows Brigham to be a prophet and Saints should esteem his words as the voice of God to them.
George A. Smith, "Disobedience of Counsel—The Indian War The result of the Same," Journal of Discourses, 26 vols. (Liverpool: F.D. and S.W. Richards, 1854), 1:192, 193
In the commencement of my remarks, I will say, that the people almost universally do not realize the importance of listening to the voice of God through His servant Brigham. . . . I bear witness before you, this day, in the name of the Lord God of Israel, that no people can treat lightly the sayings of a Prophet of God whom He places on the earth to direct His people, and prosper. I know it is impossible. . . . I knew Brigham to be a Prophet of the Lord, and esteemed his words as the voice of God to the people.