At a lodging place on the way the Lord met him and sought to put him to death. Then Zipporah took a flint and cut off her son's foreskin and touched Moses' feet with it and said, “Surely you are a bridegroom of blood to me!” So he let him alone. It was then that she said, “A bridegroom of blood”, because of the circumcision.
The Lord said to Aaron, “Go into the wilderness to meet Moses.” So he went and met him at the mountain of God and kissed him. And Moses told Aaron all the words of the Lord with which he had sent him to speak, and all the signs that he had commanded him to do. Then Moses and Aaron went and gathered together all the elders of the people of Israel. Aaron spoke all the words that the Lord had spoken to Moses and did the signs in the sight of the people. And the people believed; and when they heard that the Lord had visited the people of Israel and that he had seen their affliction, they bowed their heads and worshipped.
Exodus 4:24-31
This is a very mysterious passage. It seems best to interpret 24 in terms of a sudden, severe illness endangering Moses' life, which both he and Zipporah construed as a warning from God to attend to His will and obey His ordinance of circumcision. Nothing else will explain the performance of the rite at that particular juncture. The covenant sign had been neglected. Some commentators have suggested that it had once been an issue in their home, that Zipporah had opposed it, and for peace sake Moses had yielded against his better judgment. One wonders if in fact this is the real explanation of Moses' continued reluctance as recorded in this chapter. Had he put peace in his home before the fulfilment of his high calling? It never pays so to do; the issue must at last be faced, and it is usually much more distressing and costly when it is postponed for so long. They went back to Jethro; they would be no use to Moses in his arduous task, but rather a hindrance. But we may take leave to ask whether it would ever have come to such a painful, though temporary, separation as this, if Moses had stood for principle in the beginning, when the matter had first become an issue in the home. It is never right to do wrong, and the sacrifice of right is too great a price to pay for peace. It cost Moses pain and loneliness that, it would seem, he need not have had to suffer, and it cost Zipporah the privilege of seeing the mighty hand of God stretched out in the deliverance of His people. To refuse the will of God is always loss.