Exodus 4:24-26

24At a lodging place on the way, the LORD met Moses Hebrew him and was about to kill him. 25But Zipporah took a flint knife, cut off her son’s foreskin and touched Moses’ feet with it. The meaning of the Hebrew for this clause is uncertain. “Surely you are a bridegroom of blood to me,” she said.

26So the LORD let him alone. (At that time she said “bridegroom of blood,” referring to circumcision.)