Just wanted to summarize some thoughts on the passage before moving on to my next “all commentaries are not created equal” illustration. I think I can summarize the best thinking on the passage in a comprehensible way now that you have all been exposed to solid commentary material, as well as add a few thoughts of my own into the mix.
Exodus 4:24-26 and the Bridegroom of Blood
This passage is regularly spoken of by scholars as one of the more enigmatic texts in the Old Testament. The passage is placed in the context of Moses’ return to Egypt, but the rationale for its placement is obscure. The passage in that context reads as follows (ESV):
21 And the Lord said to Moses, “When you go back to Egypt, see that you do before Pharaoh all the miracles that I have put in your power. But I will harden his heart, so that he will not let the people go. 22 Then you shall say to Pharaoh, ” Thus says the Lord, Israel is my firstborn son, 23 and I say to you, ‘Let my son go that he may serve me.’ If you refuse to let him go, behold, I will kill your firstborn son’.”
24 At a lodging place on the way the Lord met him and sought to put him to death. 25 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!” 26 So he let him alone. It was then that she said, “A bridegroom of blood,” because of the circumcision.
The apparent incoherence of the placement and the meaning of verses 24-26 extends from the fact that it makes little sense for God to want to kill Moses right after He has called him to return to Egypt as the chosen delivered of Israel. In addition to this theological conundrum, the passage lacks clarity because the referent of certain verbs and pronouns is ambiguous, and certain expressions used in the passage have unclear meanings.
Two points of uncertainty are especially important. First, who is it that the LORD wanted to put to death? Most readers assume it is Moses since he is mentioned in the preceding verses, but verse 24 does not name him. Since it is Moses’ son (Gershom; Exod 2:22) whose foreskin is removed in verse 24, he could very well be the person under threat of death. Second, what does it mean that Zipporah, Moses’ wife (Exod 2:21), would touch the foreskin of her son to Moses’ “feet”? Two additional factors make this question even more troublesome. The name “Moses” does not appear in the Hebrew text, which literally reads “touched his feet.”
With Whom Was God Angry and Why?
It seems best to conclude that God is angry with Moses, not Gershom, since Moses is the major character in the wider context and Gershom is known only from Exod 2:22 at this point. Scholars have noted that Moses is the center of Yahweh’s attention everywhere else, even in the digressions involving Aaron (Exod 4:14, 27-29). But why would God be angry with Moses? The answer must be inferred from two considerations: (1) The Israelites born in Egypt had been circumcised, apparently (though this could be problematic) in accord with Israelite / Abrahamic procedure (Josh 5:2-9; cp. Gen 17), and (2) the circumstances of Moses’ birth and childhood (Exod 1-2). We will consider these in order.
With respect to the first item, it may be that the Israelites in Egypt practiced “Egyptian circumcision” (refers to a method, not anything religious) and so Moses and other Israelite men were not properly circumcised (see Joshua 5:2 — the “second time” reference is a point of interest). Having fled from Egypt, God may have expected to correct this before returning to Egypt (hence his anger). This is an argument from silence but the other explanations are as well.
Archaeologists and Egyptologists know that circumcision was practiced in Egypt by the Egyptians. However, Egyptian circumcision did not remove the foreskin; rather, the foreskin was split. For this reason, any Israelite born in Egypt who happened to be circumcised in this way had not been circumcised in a manner acceptable to God’s covenant. Those who take this trajectory as an explanation for God’s anger would suggest that Egyptian circumcision is hinted at in Josh 5:9 (“the reproach of Egypt”). Since Josh 5:2 informs us that some of the Israelite men were being circumcised “a second time,” it can perhaps be inferred that there was something unacceptable about any circumcision they had in Egypt. As a result, the ceremony in Josh 5 would be a second circumcision for some of the men, while it would be first circumcision for those males born in the wilderness wandering (Josh 5:4). Joshua 5:2 is really what this view hangs on. If the men of Israel who left Egypt under Moses had been properly circumcised, what’t the point of the “second time” reference?
Since the other Israelite males were circumcised prior to the conquest in Josh 5:2-9 at Gilgal (some a “second time”; Josh 5:2), it is reasonable to assume that Moses also had never been circumcised, or was circumcised according to the Egyptian custom. The narrative of Moses’ birth and childhood never states his parents had him circumcised. Had the boy been marked by Hebrew circumcision, his life would likely have been in danger in Pharaoh’s household. We can only speculate whether Pharaoh’s daughter had him circumcised in the Egyptian manner after he entered her household. In any event, he did not bear the covenant sign.
In his Exodus commentary in the WBC series, Durham notes in this regard (citing Sasson):
Sasson (JBL 85  473–74) has pointed out convincingly that Egyptian circumcision was not only performed on adults, but was, by comparison with Hebrew circumcision, merely a partial circumcision. Indeed, he contends (475–76) that circumcision may well have come to Egypt from North Syria, where it was practiced early in the third millenium B.C. For whatever reasons, the compiler who set vv 24–26 in their present context had apparently reached a conclusion confirmed by these facts. Perhaps he combined the abnormal circumstances by which the infant Moses had to be hidden away at birth with some knowledge of the Egyptian practice and even a belief that the circumcision of infant boys was a late development in Israel’s life. Quite possibly, he too was searching for some reason for Yahweh’s serious encounter. Whatever the case, he clearly believed that Moses was uncircumcised and that Yahweh determined to stop him en route to Egypt for that reason.1
Another angle is that it’s possible Moses’ mother would not have had him circumcised under the duress of Pharaoh’s edict. Perhaps she hoped that, if he was discovered, the Egyptian would have mercy on him not knowing he was a Hebrew (in the wake of Pharaoh’s law). But Pharaoh’s daughter knew immediately the baby was a Hebrew. How? It doesn’t have to be because of circumcision — why would anyone else put their kid in a basket and set him afloat on the Nile? So it’s possible Moses was not circumcised.
We just don’t know for sure how to take Josh 5:2-9 in relation to Gen 4:24-26 (or even if we should relate them). But in any event, a circumcision pacified God’s anger. Perhaps it’s as simple as Moses’ neglect to have his son circumcised — or resistance (Zipporah apparently knows that a circumcision will save Moses from God’s anger). The passage is obtuse in so many ways.
Who Was Circumcised and What Did It Mean?
We just don’t know for sure how to precisely take Josh 5:2-9 in relation to Gen 4:24-26 (or even if we should relate them). But in any event, a circumcision pacified God’s anger. Perhaps it’s as simple as Moses’ neglect to have his son circumcised — or resistance (Zipporah apparently knows that a circumcision will save Moses from God’s anger).
That the Midianites practiced circumcision is apparent from the fact that Zipporah has access to the necessary tool and knows how to perform the rite. Having chosen Moses to be His representative to deliver Israel, Moses’ laxity in this matter became an issue with God. Hence His anger that Moses had not bothered to be circumcised before leaving on his mission.
Concerning whether Moses or his son Gershom was circumcised, clarity can be gained in Zipporah’s act of touching the foreskin to the “feet.” Let’s talk about the “feet” before going on. The Hebrew word can refer to feet, legs, or genitals according to Old Testament usage (see Deut 28:57; Ezek 16:25;= [lit. “spreading your feet”]; Ruth 3:4, 7). Gaining clarity on all these issues is crucial to a coherent interpretation.
Durham notes that “feet,” here is used as a euphemism for the genitals. This makes good contextual sense in light of what ensues.
The act of touching the foreskin to the “feet” is not part of the normal ritual of circumcision. It consequently only makes sense if Zipporah has circumcised her son, Gershom, and then symbolically transferred that circumcision to Moses by taking the foreskin and touching Moses’ genitals. Under the circumstances, Moses would have been incapacitated and they were already on the way to Egypt; God was satisfied by the ritual act (Exod 4:26). Zipporah had saved Moses’ life.
In regard to the phrase “bridegroom of blood,” the phrase is obviously associated with the marital relationship (“bridegroom”). So why use the term? Moses’ status as a “bridegroom” must have some importance. It’s important.
Zipporah, the only person available to perform the rite, seizes the mandatory flint cutting tool (Josh 5:2–9; cf. Sasson, JBL 85  474) and circumcises not Moses, who would have been temporarily incapacitated by the surgery (cf. Gen 34:18–31) at a crucial time when he could no longer delay his journey, but her son. For the child, who was not to make the journey to Egypt in any case, the effects of the circumcision would be less problematic. To transfer the effect of the rite, Zipporah touched the severed foreskin of her son to the genitals of Moses, intoning as she did so the ancient formula recalling circumcision as a premarital rite: “For a bridegroom of blood you are to me!” This ancient phrase, as Mitchell [VT 19  94–105, 111–12) has demonstrated, is a phrase of marital relationship.2
In other words, circumcision was a pre-marital ritual, performed on the male infant. As the sign of the covenant, it identified men as Israelite for the sake of their women — it ensured that the married couple were both Israelites and that there was no forbidden intermarriage taking place. We have to assume that Zipporah had learned and embraced the idea that the God of the mountain she knew of by virtue of her proximity to it in Midian (Exod 3:1-2) was the God of the Israelites and the true God. This is particularly coherent if the Kenite connection involves the worship of Yahweh. Zipporah’s Her marriage to Moses linked her to the Israelite people and their covenantal relationship to Yahweh. Under normal circumstances, her husband would have been a circumcised Israelite man. This ritual of circumcision by proxy made Moses her “bridegroom of blood,” and so part of the ritual act of touching the foreskin of Gershom to Moses’ genital area “atoned” for that oversight as well.