Orson Hyde, in a letter from June 1841, reports that Joseph promised him that, in the Holy Land, he would do a work that would "greatly facilitate the gathering together of that people."
Orson Hyde, Letter to the Editor, June 15, 1841, repr. Times and Seasons 2, no. 23 (October 1, 1841): 552-53
"Since I have arrived to years of more mature reflection, and become religiously inclined, the writings of the Jewish prophets have won my affections; and the scattered and oppressed condition of that people, has enlisted the finest sympathies of my heart. Believing therefore, that the words of Hosea the prophet 2. 23, connected with your magnanimity, will prohibit the indulgence of any prejudice in your feelings against the author of this production, in consequence of his not being able, by any existing document or record, to identify himself with your nation."
"About nine years ago, a young man with whom I had had a short acquaintance, and one, too, in whom dwelt much wisdom and knowledge in whose bosom the Almighty had deposited many secrets, laid his hands upon my head, and pronounced these remarkable words: 'In due time, thou shalt go to Jerusalem, the land of thy fathers, and be a watchman unto the house of Israel; and by thy hands, shall the Most High do a good work, which shall prepare the way, and greatly facilitate the gathering together of that people.' Many other particulars were told me by him, at that time, which I do not write in this letter: But sufficient is written to show that divine appointment is claimed as the main-spring that has sent me forth from the embraces of an affectionate family, and kind friends as well as from the land that gave me birth."