“You Shall Go unto the Lamanites and Preach My Gospel unto Them”

Doctrine and Covenants 28:8–9

8 And now, behold, I say unto you that you shall go unto the Lamanites and preach my gospel unto them; and inasmuch as they receive thy teachings thou shalt cause my church to be established among them; and thou shalt have revelations, but write them not by way of commandment.
9 And now, behold, I say unto you that it is not revealed, and no man knoweth where the city Zion shall be built, but it shall be given hereafter. Behold, I say unto you that it shall be on the borders by the Lamanites.

President Joseph Fielding Smith wrote:

“The first step taken towards making known where the New Jerusalem should be built was taken in the appointment of Oliver Cowdery in August, 1830, to go to the Lamanites and preach the gospel. The time had not come in 1830 for the site for this city to be revealed, and in the attempt to make it known Hiram Page had blundered. However, the Lord did say at that time that the city should be on the borders of the Lamanites. In later revelations other brethren, including Parley P. Pratt, Peter Whitmer, Jr., and Ziba Peterson, were appointed to accompany Oliver Cowdery on this mission (see D&C, sections 31 and 33). Before Oliver Cowdery departed on this mission to the Lamanites, which was understood to be a mission to western Missouri, he was commanded to wait until after the next conference . . . After the conference he and other brethren were to leave for the border of the Lamanites, where the New Jerusalem, or Zion, would be built.”

(Church History and Modern Revelation, 2 vols. [1953], 1:136.)