Bible Verses About Avenger of Blood: Cain fears

Behold thou dost cast me out this day from the face of the earth, and from thy face I shall be hid, and I shall be a vagabond and a fugitive on the earth: every one therefore that findeth me, shall kill me.

And the Lord said to him: No, it shall not so be: but whosoever shall kill Cain, shall be punished sevenfold. And the Lord set a mark upon Cain, that whosoever found him should not kill him.