The Doctrine and Covenants/Section 32
Revelation through Joseph Smith to Parley P. Pratt and Ziba Peterson, October 1830. History of the Church 1:118-20.
1 And now concerning my servant Parley P. Pratt, behold, I say unto him that as I live I will that he shall declare my gospel and learn of me, and be meek and lowly of heart.
2 And that which I have appointed unto him is that he shall go with my servants, Oliver Cowdery and Peter Whitmer, Jun., into the wilderness among the Lamanites.
3 And Ziba Peterson also shall go with them; and I myself will go with them and be in their midst; and I am their advocate with the Father, and nothing shall prevail against them.
4 And they shall give heed to that which is written, and pretend to no other revelation; and they shall pray always that I may unfold the same to their understanding.
5 And they shall give heed unto these words and trifle not, and I will bless them. Amen.