In these chapters, we are reading of a sermon preached by Jacob to his contemporaries. Unlike some of the other Isaiah chapters which Nephi directed towards our day and those who would later have the Book of Mormon, Jacob’s words were directed at giving comfort and guidance to his contemporaries as well as to us.
Thus, it seems to me that Jacob uses Isaiah for dual purposes. The first is to express to his people that God has not and will not forget them. The second is to exhort them to continue to be faithful and to follow God. In light of this dual purpose, these verses take on added meaning.
“10 Who is among you that feareth the Lord, that obeyeth the voice of his servant, that walketh in darkness and hath no light?
11 Behold all ye that kindle fire, that compass yourselves about with sparks, walk in the light of your fire and in the sparks which ye have kindled. This shall ye have of mine hand—ye shall lie down in sorrow.”
Jacob is describing the sins of Israel that led to the Babylonian conquest. The people began to walk by their own light, rather than follow God. They claimed to be of God, but instead walked according to their own path. And because of this grave sin, they were previously punished.
Jacob is not merely describing the fulfilment of prophecy, he is also offering a warning to his people. In light of his sermon on pride in the subsequent chapters, we can see that Jacob had begun to see those same sins developing among his people. They had begun to be wealthy and to rely on their own strength and understanding. They to had begun to lose their light.
Jacob thus offers both a reminder and a warning to his people. If they did not repent, their fate would be as was Israel’s.