Then Zipporah took a sharp stone and cut off the foreskin of her son and cast it at Moses' feet, and said, "Surely you are a husband of blood to me!"
Exodus 4:25
Surrounding context
4:24 And it came to pass on the way, at the encampment, that the LORD met him and sought to kill him.
4:25 Then Zipporah took a sharp stone and cut off the foreskin of her son and cast it at Moses' feet, and said, "Surely you are a husband of blood to me!"
4:26 So He let him go. Then she said, "You are a husband of blood!"--because of the circumcision.