(24) At a night encampment on the way, the Lord encountered him and sought to kill him.
(25) So Zipporah took a flint and cut off her son’s foreskin, and touched his legs with it, saying, “You are truly a bridegroom of blood to me!”
(26) And when He let him alone, she added, “A bridegroom of blood because of the circumcision.”
(24) At a night encampment on the way: This is a very difficult passage. We will offer just one of various options for understanding it.
The Lord encountered him and sought to kill him: Because no reason is given, it is natural to conclude that this is somehow related to the “night encampment” (literally, “inn”). The Midrash (see below) understands the Torah’s explicit mention of the overnight as indicating some delay on Moses’ part. When he stopped for the night, Moses could have performed his son’s circumcision then and there, but he failed to do so. However, we can also understand the overnight stay on the road as meaning that the initial stage of God’s elaborations to Moses is complete, and the Almighty therefore now proceeds to the second stage.
(25) So Zipporah took a flint and cut off her son’s foreskin: We were informed earlier that Zipporah bore Moses a son, who was given the name “Gershom” (2:22). But here Moses and Zipporah already have two sons (“So Moses took his wife and sons,” v. 20). And later we learn that the second son was named “Eliezer” (18:4).
According to the Midrash, Moses’ second son was born just before Moses left Midian to return to Egypt. Moses had not circumcised his son because the stress of road travel poses a danger to an infant, and circumcision in such situations must therefore be postponed. But once Moses had stopped for the night (“At a night encampment on the way”) his first duty was to circumcise his son, and this delay was the reason for the near-tragedy that ensued.
And touched his legs with it: Moses himself was unable to take any action, probably because he was near death at that point.
Saying, “You are truly a bridegroom of blood to me!”: Zipporah’s connection to Moses, previously due primarily to Moses’ status as heir to her father Jethro’s spiritual legacy, is now transformed into a connection of blood; that is, a connection rooted in a physical reality.
(26) And when He let him alone: Moses is now recovering.
She added, “A bridegroom of blood because of the circumcision”: The conclusion we are to draw from this is that circumcision is one of the central foundations of all Jewish existence.
One of various options for understanding this passage is:
As mentioned earlier, the Midrash believes that the cause of these events was Moses’ delay in circumcising his son. But the question then becomes: If Moses could neglect performing circumcision, a commandment of paramount importance in Judaism already for hundreds of years since Abraham’s time, then what kind of national leader is Moses fit to become? But if, on the other hand, Moses was justified in postponing his son’s circumcision, why, then, did God want to kill him?
As already noted above, this passage becomes clear when understood in the context of the ideas of Rabbi I. L. Ashkenazi (Manitou), which consider the dynamics of Moses’s personality on two covenantal levels: the Abrahamic covenant (God’s covenant with the Patriarchs), and the Sinai covenant between God and the nation of Israel that left Egypt.
The essence of Abraham’s covenant is to unite the ideals of mercy and justice (Gen. 18:19), and to see the Jewish people as a family that has a direct connection with God, through its existence as an autonomous nation living in its own Land. However, this covenant includes no formalized system of commandments.
The Sinai covenant, on the other hand, is a covenant of laws and commandments that regulate the life of the Jewish people as a society (and not merely a family). It is this kind of covenant that resonates with Moses’ personal inclinations and character.
Circumcision is a component of both of those covenants, but its meaning is different in each. In the Sinai covenant, circumcision is, essentially, one of the Torah’s many (613) commandments. But in Abraham’s covenant, circumcision is a symbol of the covenant itself (we note in passing that this is why the accepted Hebrew term for circumcision is Brit Milah, “The Covenant of Circumcision.” No other commandment in the Torah has the word brit, “covenant”, prefixed to its name).
By assuming the role of leader of the Exodus, Moses has agreed to lead the descendants of the Patriarchs out of Egypt. But he is still not feeling or acknowledging the importance of the Abrahamic covenant. When Moses goes to Egypt to bring the Jewish people out, and to enter them into the Sinai covenant (“And when you have freed the people from Egypt, you shall worship God at this mountain,” 3:12), he already feels himself a part of the new, Sinai covenant, and has no desire to enter his newborn son into Abraham’s covenant.
This does not mean that Moses is actually neglecting the commandment of circumcision. He simply considers it one of the many Sinai commandments, and expects to circumcise his son simultaneously with the rest of the Jewish people as a strict prerequisite (12:48) to performing the first Passover sacrifice on the eve of the Exodus from Egypt.
In other words, Moses makes a clear distinction between the Sinai covenant and the covenant of the Patriarchs.
Moses considers the “covenant of ideals” weak and ineffective, and seeks to replace it with the “covenant of commandments,” which establishes objective laws and explicit norms. Moses has already decided that the new covenant will supplant the former. This is not negligence or indifference on Moses’ part, but merely the innocent mistake of a great man.
God tells Moses in response: “If that is how you feel, then you deserve to die. The Sinai covenant will complement the Abrahamic covenant, but cannot replace or abolish it. The ideals of the Patriarchs are primary. They are the goal, and the Sinai commandments are only a tool for implementing them. Without this connection, it makes no sense for you even to lead the Jews out of Egypt.” And if so, then Moses’ life also makes no sense, and he must die.
Moses’ wife Zipporah, who comes from Midian, maintains a connection with the heritage of Abraham, which enables her to act here in opposition to Moses and as a counterbalance to him. Thanks to Zipporah’s background, she understands the problem and circumcises their son, thereby saving Moses’ life.
The mistake of separating the commandments from the ideals they are intended to support, by falsely absolutizing those commandments, has been an important problem in Judaism for many centuries, and continues to be so even in our time. If Judaism is to live and develop in our generation, it is critical that we not repeat Moses’ mistake.
In his two lessons to Moses – at the Burning Bush, and in the incident of his son’s circumcision – God showed Moses that he would only be continuing Abraham’s work, both physically and spiritually. Founding an entirely new nation was not at all a part of God’s plan. Divine revelation did not begin at Sinai, it only continued there. The life of the Jewish people did not begin at Sinai. It began with Abraham.
 See §1.3.
 See Bible Dynamics on Genesis, §18.16.
 In Numbers 18:19 we find the expression “brit melach olam hi,” “It shall be an everlasting covenant of salt.” But in that case, the word “brit” is more a description of the commandment than its actual name.
 Zipporah, through the circumcision of her son and the covenant of Abraham, is also connected with the Land of Israel. As the Abrahamic covenant is realized in that which is natural, immanent, and palpable from within, Zipporah also connects Moses with this covenant of naturalness. Separated from Zipporah (in the process of the giving the Torah), Moses transitions fully to the Divine Transcendental Revelation, and therefore cannot enter the Land of Israel, which requires the property of naturalness. Later (Num. 12:1 ff.), Miriam and Aaron want to reunite Moses and Zipporah precisely for that purpose ̶ to restore the balance of transcendental and immanent Revelation within Moses, in order to enable him to enter the Land of Israel, and them with him. All this will be discussed in greater detail in our commentary on the given passage in Numbers.