Seth, as far as the biblical record is concerned, is the third son of 'Adam and Chavah. Abel is dead and Cain is banished to the land of Shinar. It is a normal Hebrew custom that when a man and wife lose their sons to disease or war, that the next son takes upon the rights and inheritance of the firstborn son. However, the story of Abel and Cain paints us a picture of the firstborn son in God's eyes, not man's. The firstborn son in God's eyes is the one in whom HIS Word is found. The first picture of this is in the story of Cain and Abel.

Cain, the firstborn of the flesh, offers only his works. Abel, the firstborn of the Spirit, offers his works preceeded by a sacrifice (the blood of a lamb). Normally, with two sons gone, Adam would appoint his next son to replace the firstborn Cain, but YHVH reveals His pattern and His appointment.

Bere’shiyt (Genesis) 4:25And Adam knew his wife again; and she bare a son, and called his name Seth: For God, said she, hath appointed me another seed instead of Abel, whom Cain slew.

The name Seth is from the Hebrew verbal root shiyth (שית) which means to appoint or to place. So you can see by this verse that God has deemed the firstborn in His eyes to replace the man of faith, Abel, rather than Cain. A subtle hint, but a profound one as well, for this will be the pattern for God's children throughout the rest of Scripture.

Next word is Enosh.

Shalom Alecheim!