The Scofield Bible Commentary, by Cyrus Ingerson Scofield, [1917], at sacred-texts.com
Genesis Chapter 6
sons of God
Some hold that these "sons of God" were the "angels which kept not their first estate" (Jde 1:6). It is asserted that the title is in the Old Testament exclusively used of angels. But this is an error (Isa 43:6). Angels are spoken of in a sexless way. No female angels are mentioned in Scripture, and we are expressly told that marriage is unknown among angels. (Mat 22:30).
The uniform Hebrew and Christian interpretation has been that verse (Gen 6:2) marks the breaking down of the separation between the godly line of Seth and the godless line of Cain, and so the failure of the testimony to Jehovah committed to the line of Seth (Gen 4:26). For apostasy there is no remedy but judgment; (Isa 1:2-7); (Isa 1:24); (Isa 1:25); (Heb 6:4-8); (Heb 10:26-31). Noah, "a preacher of righteousness," is given 120 years, but he won no convert, and the judgment predicted by his great-grandfather fell; (Jde 1:14); (Jde 1:15); (Gen 7:11).
imagination
Or, the whole imagination. The Hebrew word signifies not only the imagination but also the purposes and desires.
repented the LORD
(See Scofield); (Zac 8:14).
walked
Noah and Enoch are the two antediluvians of whom it is said that they "walked with God" (Gen 5:24); (Gen 6:9).
Enoch, "translated that he should not see death" (Heb 11:5) becomes a type of the saints who will be "caught up" before the great tribulation; (Th1 4:14-17); (Rev 3:10); (Dan 12:1); (Mat 24:21).
Noah, preserved through the Flood, is a type of the Israelitish people who will be preserved through the tribulation (Jer 30:5-9). See "Tribulation"; (Psa 2:5); (Rev 7:14).
ark
"Ark": type of Christ as the refuge of His people from judgment (Heb 11:7). In strictness of application this speaks of the preservation through the "great tribulation" (Mat 24:21); (Mat 24:22) of the remnant of Israel who will turn to the Lord after the Church (typified by Enoch, who was translated to heaven before the judgment of the Flood) has been caught up to meet the Lord; (Gen 5:22-24); (Th1 4:15-17); (Heb 11:5); (Isa 2:10); (Isa 2:11); (Isa 26:20-21). But the type also has a present reference to the position of the believer "in Christ" (Ep 1.), etc. It should be noted that the word translated "pitch" in (Gen 6:14) is the same word translated "atonement" in (Lev 17:11) etc. It is atonement that keeps out the waters of judgment and makes the believer's position "in Christ" safe and blessed.
two of every sort
Compare (Gen 7:2).
In addition to two animals, etc, commanded (Gen 6:19) to be preserved for future increase ("they shall be male and female"), the further command was given more than 100 years later to take of clean beasts, i.e, acceptable for sacrifice, seven each. Exodus gives ten such beasts, or but seventy in all. Modern ships carry hundreds of live beasts, with their food, besides scores of human beings.