This reference comes closer to a citation, with a large portion of the phrase repeated from the Savior’s words in 3 Nephi:
3 Nephi 27:20
20 Now this is the commandment: Repent, all ye ends of the earth, and come unto me and be baptized in my name, that ye may be sanctified by the reception of the Holy Ghost, that ye may stand spotless before me at the last day.
Mormon has indicated that faith may be established upon the words of other who have experience with the divine. For Mormon, the best example of such communication with the divine is the appearance of the Atoning Messiah at Bountiful. Of course we understand that one must have faith in that event, but for Mormon is was a solid reality upon which firm faith could be built. Because that had happened, we may understand (and therefore have faith) that the other promises of God will be fulfilled.