The Bible refers to Noah as ( tanim) … which usually means having a morally pure heart. The word “tanim” can mean ” without blemish, without defect, sound, healthful, without spot, unimpaired. We see that the Hebrew meaning of the word tanim could mean more than only moral perfection.
So, Noah was righteous because of his faith, but here we see the word could refer to Noah’s perfection as being without physical blemishes and not spiritual blemishes –– sin. We are not speaking of physical perfection by suggesting that Noah was without skin blemishes. We are speaking of Noah as being uncontaminated physically from the fallen angels.
Genetic contamination came from the fallen angels. Read the book of Leviticus for the words “without blemish” which refers to sacrificial offerings to the Lord. These offerings had to be perfect and without blemish. Remember “tanim” means without blemish and is the technical word for bodily and physical perfection– not moral. It is used regarding the animals of sacrificial purity. It is rendered “without blemish” in many passages of the Old Testament. This shows that Genesis 6:9 does not necessarily speak of Noah’s moral perfection. In fact, the law was so strict that even people who had physical defects were forbidden from certain activities.
Stop! Read Leviticus 21:17-23. ( this refers to who may serve the Lord in the sanctuary). What does all this mean to our study? First of all, we know that the perfect sacrifice to redeem mankind had to be morally pure without sin. Second, the perfect sacrifice could not be contaminated physically–that is, the sacrifice could not be part human and part alien. He had to be 100% from the human bloodline. This helps us understand that Noah was perfect and as we shall see later why Mary was a Virgin. Noah had not been contaminated by the seed of the fallen angels. I believe it means that genetically, Noah had an unblemished genealogy.
Noah and his ancestors had not allowed themselves to be genetically contaminated with the fallen angels or their offspring — the Nephilim. God considered Noah just, righteous, and blameless because he trusted in God, just as Abraham had trusted in God. Noah’s wife and sons had not contaminated themselves genetically by becoming involved with the fallen angels. What about Noah’s three sons? (Reference Lindsay’s book, pgs. 138-139.)