Throughout the Old Testament, Jehovah is figured as a rock; he is the "Rock of . . . salvation" (Deuteronomy 32:15) and "the head stone of the corner" (Psalms 118:22). This characterization highlights the Lord's strength and immutability. When Daniel sees a vision of the "stone . . . cut out of the mountain without hands," that stone is a symbol of the Jehovah's power and the inevitable triumph of Israel (Daniel 2:45). He is, in Isaiah "the rock whence [we] are hewn" (Isaiah 51:2); the covenant people of Jehovah are, quite literally, chips off the old block.
But my favorite representation of Jehovah-as-Rock comes from the book of Exodus. During their journey through the wilderness, the children of Israel find themselves parched with thirst, and when they complain to Moses, the Lord gives him instructions: "Go on before the people, and take with thee of the elders of Israel; and thy rod, wherewith thou smotest the river, take in thine hand, and go. Behold, I will stand before thee there upon the rock in Horeb; and thou shalt smite the rock, and there shall come water out of it, that the people may drink" (Exodus 17:5-6). Here Jehovah, as Rock, is figuratively smitten to relieve the suffering of his covenant people, anticipating Christ's suffering on the cross and that moment when "one of the soldiers with a spear pierced his side, and forthwith came there out blood and water" (John 19:34).
In the New Testament and Book of Mormon, Christ's status as the Rock of our Salvation provides a safe foundation on which we can safely endure the storms of life. Helaman taught his sons "that it is upon the rock of our Redeemer, who is Christ, the Son of God, that ye must build your foundation; that when thhe devil shall send forth his mighty winds, yea, his shafts in the whirlwind, yea, when all his hail and his mighty storm shall beat upon you, it shall have no power over you to drag you down to the gulf of misery and endless wo, because of the rock upon which ye are built" (Helaman 5:12). Christ's status as the rock is always a comfort and a protection to his covenant people.
Christ's position as the Rock of Israel is always a comfort and a protection to his covenant people except in the eighth chapter of Isaiah. Isaiah warns, "And he shall be for a sanctuary; but for a stone of stumbling and for a rock of offence to both the houses of Israel, for a gin and for a snare to the inhabitants of Jerusalem. And many among them shall stumble, and fall, and be broken, and be snared, and be taken" (Isaiah 8:14-15). In these verses, the comfort and protection associated with Christ's status as the Rock of Israel seems to turn into fear and danger. The paraphrased footnote for these verses in the Bible printed by the Church of Jesus Christ of Latter-day Saints suggests that here, Jehovah's status as the Rock inspires "security for those who trust him, but dismay and suffering for unbelievers." This is a fine interpretation--but the text doesn't actually distinguish between those who believe in and those who reject Jehovah. However, the text does recall the phraseology of 1 Samuel 2:2-4, and Christ's depiction as a "rock of offence" makes much more sense (to me) in that context.
In 1 Samuel 2, Hannah sings a song of praise in celebration of her miraculous conception: "There is none holy as the Lord: for there is none beside thee: neither is there any rock like our God. . . . The bows of the mighty men are broken, and they that stumbled are girded with strength" (1 Samuel 2:2, 4). Why would Isaiah reference this song of praise celebrating a divinely orchestrated conception? Because in the larger context of these verses about Jehovah's status as a "rock of offence," Isaiah has told Israel and Judah that his own children have also been appointed by the Lord for signs: "Behold, I and the children whom the Lord hath given me are for signs and for wonders in Israel from the Lord of hosts" (8:18). Isaiah's description of Jehovah as a "rock of offence" hearkens back to Hannah's characterization of God as a "rock" (the Hebrew is tsuwr in both verses), and recognizing the link between these verses fundamentally shifts our understanding of Isaiah.
When Hannah writes about God as a rock, she argues that stumbling produces strength. Her characterization of Christ as a stumbling stone insists on a fall forward, for the good of those that stumble and to the confounding of their seemingly more powerful enemies. Hannah's stumbling stone, in other words, is in harmony with Moroni's characterization of Christ: "I give unto men weakness that they may be humble; and my grace is sufficient for all men that humble themselves before me; for if they humble themselves before me, and have faith in me, then will I make weak things become strong unto them" (Ether 12:27). When Isaiah writes that Jehovah is a "rock of offence" and prophesies that many shall stumble, he reminds Israel of the Lord's capacity to protect the weak from "mighty men" and insists that these humbling calls to repentance and the trials that will follow--like rocks of offence--will lead individuals and, collectively, all of Israel to greater strength in and through Christ.
Truly, great are the words of Isaiah!