Genesis 17:10-12 Gen. 17:10-12
10 This is my covenant, which ye shall keep, between me and you and thy seed after thee; Every man child among you shall be circumcised. 11 And ye shall circumcise the flesh of your foreskin; and it shall be a token of the covenant betwixt me and you. 12 And he that is eight days old shall be circumcised among you, every man child in your generations, he that is born in the house, or bought with money of any stranger, which is not of thy seed.
Exodus 4:24-26 Ex. 4:24-26
24 And it came to pass by the way in the inn, that the LORD met him, and sought to kill him. 25 Then Zipporah took a sharp stone, and cut off the foreskin of her son, and cast it at his feet, and said, Surely a bloody husband art thou to me. 26 So he let him go: then she said, A bloody husband thou art, because of the circumcision.
(Relation)