New Defender's Study Bible Notes
5:30 begat sons. All the antediluvian patriarchs are said to have begotten sons and daughters, probably many of each, so the world population grew explosively. The names listed are not those of the firstborn, but of the one in each family who would serve as spiritual leader of his people and who would be in the line of promise. In Noah’s case, his brothers and sisters were probably ungodly like the rest of their generation, finally perishing in the flood.