Genesis 4:17, 25-26

Cain knew his wife, and she conceived and bore Enoch. When he built a city, he called the name of the city after the name of his son, Enoch.

And Adam knew his wife again, and she bore a son and called his name Seth, for she said, “God has appointed for me another offspring instead of Abel, for Cain killed him.” To Seth also a son was born, and he called his name Enosh. At that time people began to call upon the name of the LORD.