And Noah and his sons hearkened unto the Lord, and gave heed, and they were called the sons of God. And when these men began to multiply on the face of the earth, and daughters were born unto them, the sons of men saw that those daughters were fair, and they took them wives, even as they chose...And in those days there were giants on the earth, and they sought Noah to take away his life; but the Lord was with Noah, and the power of the Lord was upon him. And the Lord ordained Noah after his own order, and commanded him that he should go forth and declare his Gospel unto the children of men, even as it was given unto Enoch. And it came to pass that Noah called upon the children of men that they should repent; but they hearkened not unto his words; And also, after that they had heard him, they came up before him, saying: Behold, we are the sons of God; have we not taken unto ourselves the daughters of men? And are we not eating and drinking, and marrying and giving in marriage? And our wives bear unto us children, and the same are mighty men, which are like unto men of old, men of great renown. And they hearkened not unto the words of Noah.
Compare Genesis 6:2-4, which has long been a point of speculation for Bible commentators and remained such in the 19th century:
That the sons of God saw the daughters of men that they were fair; and they took them wives of all which they chose. And the Lord said, My spirit shall not always strive with man, for that he also is flesh: yet his days shall be an hundred and twenty years. There were giants in the earth in those days; and also after that, when the sons of God came in unto the daughters of men, and they bare children to them, the same became mighty men which were of old, men of renown.
Almost every phrase from Genesis shows up in some way in the BoMoses passage, but they have been recontextualized in a way that makes very clear that "sons of God" refers to human rather than to divine beings. (I love the bit about the giants trying to kill Noah. Joseph Smith had quite the imagination.) The problem, though, is that in the Ancient Near East the phrase "sons of God" generally referred to divine beings. Joseph Smith also separates the giants from the mighty men. The truth is that in rewriting this passage, the prophet has made it much less Near Eastern than it was in Genesis.
Moses 8 also says,
And it repented Noah, and his heart was pained that the Lord had made man on the earth, and it grieved him at the heart. And the Lord said: I will destroy man whom I have created, from the face of the earth, both man and beast, and the creeping things, and the fowls of the air; for it repenteth Noah that I have created them, and that I have made them; and he hath called upon me; for they have sought his life.
Compare Genesis 6:6-7:
And it repented the Lord that he had made man on the earth, and it grieved him at his heart. And the Lord said, I will destroy man whom I have created from the face of the earth; both man, and beast, and the creeping thing, and the fowls of the air; for it repenteth me that I have made them.
The concept that the Lord "repented" had long been considered problematic by Greek-influenced thinkers for whom God had to be a morally perfect being incapable of regretting his past actions. But obviously there's no problem with a changeable or morally fallible God in the Ancient Near Eastern context. The God of Genesis, here, has predictably anthropomorphic characteristics. The God of the Book of Moses, on the other hand, fits predictably 19th-century conceptions.
Joseph's revelations, frankly, contain so many of these intrusive midrashic expansions that I'm at a loss as to how so many obviously bright Mormon scholars can see them as authentic works of the historical persons to whom they are attributed.
-Chris