Look at the blessing that was given to Joseph, the son of Jacob.
"22 ¶ Joseph is a fruitful bough, even a fruitful bough by a well; whose branches run over the wall:
23 The archers have sorely grieved him, and shot at him, and hated him:
24 But his bow abode in strength, and the arms of his hands were made strong by the hands of the mighty God of Jacob; (from thence is the shepherd, the stone of Israel
25 Even by the God of thy father, who shall help thee; and by the Almighty, who shall bless thee with blessings of heaven above, blessings of the deep that lieth under, blessings of the breasts, and of the womb:
26 The blessings of thy father have prevailed above the blessings of my progenitors unto the utmost bound of the everlasting hills: they shall be on the head of Joseph, and on the crown of the head of him that was separate from his brethren. "
(Genesis 49)
Joseph's branches run over the wall, unto the utmost bound of the everlasting hills. Where is the fulfillment of this prophecy, if not through Lehi and his sons? Joseph, not Judah, had the principal blessing.
Take a look at Ephraim's blessing:
"17 And when Joseph saw that his father laid his right hand upon the head of Ephraim, it displeased him: and he held up his father’s hand, to remove it from Ephraim’s head unto Manasseh’s head.
18 And Joseph said unto his father, Not so, my father: for this is the firstborn; put thy right hand upon his head.
19 And his father refused, and said, I know it, my son, I know it: he also shall become a people, and he also shall be great: but truly his younger brother shall be greater than he, and his seed shall become a multitude of nations. "
(Genesis 48)
Ephraim's posterity was to become a multitude of nations.
Now look at this prophesy of Moses:
"26 I call heaven and earth to witness against you this day, that ye shall soon utterly perish from off the land whereunto ye go over Jordan to possess it; ye shall not prolong your days upon it, but shall utterly be destroyed.
27 And the Lord shall scatter you among the nations, and ye shall be left few in number among the heathen, whither the Lord shall lead you.
28 And there ye shall serve gods, the work of men’s hands, wood and stone, which neither see, nor hear, nor eat, nor smell.
29 But if from thence thou shalt seek the Lord thy God, thou shalt find him, if thou seek him with all thy heart and with all thy soul.
30 When thou art in tribulation, and all these things are come upon thee, even in the latter days, if thou turn to the Lord thy God, and shalt be obedient unto his voice;
31 (For the Lord thy God is a merciful God

he will not forsake thee, neither destroy thee, nor forget the covenant of thy fathers which he sware unto them. "
(Deuteronomy 4)
Moses fortold that his people would be scattered across the nations, where they would be few in number. He even intimates the the Lord himself will guide them when he says "whither the Lord shall lead you." Where is this more evident than in the case of Lehi and his posterity? Lehi was led by the lord to journey with his family to America. His sons Laman and Lemuel joined with the native inhabitants who worshipped idols of wood and stone and gold and silver. Yet sometimes they repented and returned to worship the Lord God, and God did remember the covenant that he made with their fathers.
Isaiah saw our day, and described it accurately:
"13 Wherefore the Lord said, Forasmuch as this people draw near me with their mouth, and with their lips do honour me, but have removed their heart far from me, and their fear toward me is taught by the precept of men:
14 Therefore, behold, I will proceed to do a marvellous work among this people, even a marvellous work and a wonder: for the wisdom of their wise men shall perish, and the understanding of their prudent men shall be hid. "
(Isaiah 29)
So in a day when people give God lip service, and fear him, but do not love him, God is going to do a "marvelous work and a wonder" which shall humble their wise and prudent men. What is this marvelous work and a wonder?
"11 And the vision of all is become unto you as the words of a book that is sealed, which men deliver to one that is learned, saying, Read this, I pray thee: and he saith, I cannot; for it is sealed:
12 And the book is delivered to him that is not learned, saying, Read this, I pray thee: and he saith, I am not learned. "
(Isaiah 29)
What book does this describe, if not the Book of Mormon?