Exodus 4:24-26

Now it came about at the lodging place on the way that the LORD met him and sought to put him to death. Then Zipporah took a flint and cut off her son’s foreskin and threw it at Moses’ feet, and she said, “You are indeed a bridegroom of blood to me.” So He let him alone. At that time she said, “You are a bridegroom of blood”—because of the circumcision.