This revelation was not included in the Book of Commandments. It was published in the 1835 Doctrine and Covenants with revised wording. Footnotes and commentary can be found in The Joseph Smith Revelations: Text and Commentary.
From KRB, 89-91 (cf. LDS and RLDS D&C 57)
Revelation received at Independence, Jackson County, Missouri,
on 20 July 1831 indicating the place of the City of Zion
and the gathering
Revelation given in independence July th[e] 20 1831 shewing that to be the place of the city of Zion and the gathering
Hearken O ye Elders of my church saith the lord your God who have assembled yourselves together according to my commandments in this land which is the land of Missouri which is the land which I have appointed and consecrated for the gathering of the saints
Wherefore this is the land of promise and the place for the city of Zion yea and thus saith the Lord your God if ye will receive wisdom here is wisdom behold the place which is now called Independence is the center place and the spot for the temple is lying westward upon a lot which is not far from the courthouse
Wherefore it is wisdom that the Land should be purchased by the saints and also every tract lying westward even unto the line run[n]ing directly between Jew and Gentile and also every tract bordering by the prairies in asmuch as my disciples are enabled to buy lands behold this is wisdom that they may obtain it for an everlasting inheritance
and let my servant Sidney Gilbert stand in the office which I have appointed him to receive monies to be an agent unto the church to buy lands in all the regions round about inasmuch as can be in righteousness and as wisdom shall direct
and let my servant Edward [Partridge] stand in the office which I have appointed unto him to divide unto the saints their inheritance even as I have commanded and also them whom he has appointed to assist him
And again verily I say unto you let my servant Sidney Gilbert plant himself in this place and establish a store that he may sell goods without fraud that he may obtain money to buy lands for the good of the saints and that he may obtain provisions and whatsoever things the di[s]ciples may need to plant them in their inheritance
and also let my servant Sidney [Gilbert] obtain a licence [license] (Behold here is wisdom and whoso readeth let him understand) that he may send goods also unto the Lamanites even by whom I will as clerks employed in his service and thus the gospel may be preached unto them.
And again verily I say unto you let my servant William [W. Phelps] also be planted in this place and be established as a printer unto the church and lo if the world receiveth his writings (Behold this is wisdom) let him obtain whatsoever he can obtain in righteousness for the good of [the] saints and let my servant Oliver [Cowdery] assist him even as I have commanded in whatsoever place I shall appoint unto him to copy and to correct and select &c that all things may be right before me as it shall be proved by the spirit through him And thus let those of whom I have spoken be planted in the land of Zion as speedily as can be with their families to do these things even as I have spoken
And now concerning the gathering let the Bishop and the agent make preparations for those families which have been commanded to come to this land as soon as possable [possible] and plant them in there [their] inheritance and unto the residue of both Elders and members further directions shall be given hereafter even so Amen