Genesis 5:6

And Seth lived an hundred and five years, and begat Enos:

And Seth lived an hundred and five years. In enumerating these patriarchs in the pious family of Seth, the sacred historian, who wrote under the direction of the Spirit, mentions with minute particularity the year in the life of each successive member in the series, at the birth of his son, who is named, the number of years he lived after that, together with the fact of his having other children, and the entire age he had attained when he died. This course was not followed in regard to the Cainite patriarchs, because that family was soon to become wholly extinct, and to have no future history. But the Sethites would possess an interest for the Church in all time coming, and therefore their genealogies are given, in order to demonstrate the faithfulness of God to His promise concerning a Redeemer.