The book of Ether in the Book of Mormon is a relatively brief abridgement of the record of Ether which was recorded in 24 plates of gold and recovered by the people of King Limhi during their unsuccessful attempt to locate the land of Zarahemla (Mosiah 9:9). According to Moroni, what we have in the book of Ether (minus Moroni's own commentary) does not even represent a hundredth part of what Ether wrote in that record (Ether 15:33). While we do not yet have Ether's full record, we do have what may be a fragment from that account in the prophecies of Alma when he entrusted these records to his son Helaman (Alma 37:21-32).
The Book of Ether recounts how the brother of Jared, fearing that his people would have to make a lengthy journey across the sea in darkness, carefully prepared sixteen small transparent stones and asked the Lord to touch them so that they would be filled with light.
Touch these stones, O Lord, with thy finger, and prepare them that they may shine forth in darkness; and they shall shine forth unto us in the vessels which we have prepared, that we may have light while we shall cross the sea (Ether 2:4).
Seeing the great faith of the Jaredite's founding pioneer prophet, the Lord responded to this prayer by touching each of these stones, one by one with his finger in full view of the brother of Jared. The prophet then put two of these stones in each vessel to give light to his people during their lengthy journey across the stormy waters.
And thus the Lord caused stones to shine in darkness, to give light unto men, women, and children, that they might not cross the great waters in darkness (Ether 6:3).
In his teachings to his son Helaman Alma quotes an otherwise unattested prophecy from the Lord about the Jaredites which seems to evoke the language and events of this earlier encounter.
And the Lord said: I will prepare unto my servant Gazelem, a stone, which shall shine forth in darkness unto light, that I may discover unto my people who serve me, that I may discover unto them the works of their brethren, yea, their secret works, their works of darkness and abominations (Alma 37:23).
Here the Lord in the Ether fragment uses the language of the brother of Jared to describe what he will do hundreds of years later to an unrepentant Jaredite people but with a new and interesting twist. The Lord because of the great faith of one man once touched stones that they might give light to his people when crossing the sea that they would not have to cross in darkness. Now, when the Jaredites had become unrepentant and chose works of darkness, he again prepares a stone to give light, but in this case, to reveal the secret works of the wicked which they sought to keep hidden in the dark, but which in spite of their efforts God would cause, through the seer's gift, to “shine forth” and be known to their shame.