Genesis 4:17 New Revised Standard Version (NRSV)
Beginnings of Civilization
17 Cain knew his wife, and she conceived and bore Enoch; and he built a city, and named it Enoch after his son Enoch.
Genesis 4:25 New Revised Standard Version (NRSV)
25 Adam knew his wife again, and she bore a son and named him Seth, for she said, “God has appointed[a] for me another child instead of Abel, because Cain killed him.”