Exodus 4:23-25

Amplified Bible

²³ So I say to you, ‘Let My son go so that he may serve Me’; and if you refuse to let him go, behold, I will kill your son, your firstborn.”’”

²⁴ 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].^{(A) 25 [a]}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!”