Exodus 4:24-26

Now it happened at the lodging place, that the LORD met Moses and sought to kill him [making him deathly ill because he had not circumcised one of his sons]. [Gen 17:9-14] Then Zipporah took a flint knife and cut off the foreskin of her son and threw it at Moses’ feet, and said, “Indeed you are a husband of blood to me!” So He let Moses alone [to recover]. At that time Zipporah said, “You are a husband of blood”—because of the circumcision.