Exodus 4:20-26

20Then Moses took his wife and his sons and set them on a donkey, and he returned to the land of Egypt. And Moses took the rod of God in his hand.

21And the Lord said to Moses, “When you go back to Egypt, see that you do all those wonders before Pharaoh which I have put in your hand. But I will harden his heart, so that he will not let the people go.

22Then you shall say to Pharaoh, ‘Thus says the Lord: “Israel is My son, My firstborn.

23So I say to you, let My son go that he may serve Me. But if you refuse to let him go, indeed I will kill your son, your firstborn.” ’ ”

24And it came to pass on the way, at the encampment, that the Lord met him and sought to kill him.

25Then 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!”

26So He let him go. Then she said, “You are a husband of blood!”—because of the circumcision.