Section 45 of the Doctrine and Covenants was originally called a prophecy. Along with the Law (section 42), it helped to start the continuing movement to Ohio, dictate the method of growth for this new Church and initiate the New Testament revision which would later include Joseph Smith-Mathew, as is currently in the Pearl of Great Price. Also with this we get a rare document, a letter written in Joseph Smith's own hand. The letter is to Hyrum with reports of success in missionary work and for the new home for the Saints.