Cross reference
Exodus 4:25
25 Then Zipporah took a flint, and cut off the foreskin of her son, and cast it at his feet; and she said, "Surely you are a bridegroom of blood to me."
Joshua 5:2-3
2 At that time Yahweh said to Joshua, Make you flint knives, and circumcise again the children of Israel the second time.
3 Joshua made himself flint knives, and circumcised the children of Israel at the hill of the foreskins.
Genesis 17:14
14 The uncircumcised male who is not circumcised in the flesh of his foreskin, that soul shall be cut off from his people. He has broken my covenant."
2 Samuel 16:7
7 Thus said Shimei when he cursed, Be gone, be gone, you man of blood, and base fellow: