Though the brief and “bloody” episode of the circumcision that Zipporah performed is tucked away in the OT, there have been scores of articles and essays written on it. It would be too tedious to list them all here, but for the record the ones I found helpful were written (in various commentaries and journals) by William Propp “That Bloody Bridegroom,” Ronald Allen “The ‘Bloody Bridegroom’ in Exodus 4:24-26,” Bernard Robinson “Zipporah to the Rescue: A Contextual Study of Exodus IV 24-6,” Julian Morgenstern “The ‘Bloody Husband’ (?) (Exod. 4:24-26) Once Again,” and commentaries by Brevard Childs, Peter Enns, Nahum Sarna, Terrence Fretheim, John Calvin, and a few others. One should also consult Wellhausen’s etiological description, as well as important Jewish commentaries.
We note from the outset that the Hebrew text is anything but crystal clear: On whose “feet” does Zipporah wipe (nagah) the bloody foreskin? Does ‘feet’ (regel) mean legs, feet, or private parts here? Which son does Zipporah circumcise? Who is the ‘bridegroom’ (hatan) of blood? What does ‘bridegroom’ (hatan) mean here – relative, in-law, or wife’s father? Who let whom go? Certainly there are more questions that are not so easy to answer; the LXX is only somewhat helpful on this passage.
Here are a few things from the passage that can be stated with relative certainty: 1) Yahweh is angry with Moses and put him in a death grip. 2) Zipporah circumcised her son. 3) Zipporah’s bloody actions rescued Moses from death.
Here are two major OT episodes that parallel this passage grammatically and theologically: 1) Look back – Gen 32.24-30 – Jacob wrestling with the man/angel. In the Moses episode and in the Jacob episode, there was a struggle (someone held someone), both struggles happened during a return journey, both involve a “touching” (nagah), both involve resistance to God’s call, both are followed by a favorable meeting with and kiss from a brother (Esau, Aaron). You’ll find more parallels as well, making the connection quite tight.
2) Look forward – the Passover. Both the Moses episode and the Passover involve the anger of Yahweh against sin, cutting, a son(s), blood, smearing (nagah) blood, and death being avoided by the shedding of blood. Again, you’ll find more parallels, making the connection even more striking.
As Enns and Childs both note, circumcision here is quite important, also making the reader recall Gen 17, where the penalty for being uncircumcised was to be “cut off” from the covenant community. Perhaps Yahweh is angry with Moses for unbelief and disobedience (cf. Ex 3.1-4.17, esp. 4.14), perhaps he is angry with Moses for not circumcising his son (possibly Gershom). Perhaps both. Either way, Yahweh was angry with Moses for sin, there was a cutting and a blood-shedding; the wiping of the bloody foreskin on (possibly) Moses may symbolize a cutting off in the stead of Moses. Again, this has Passover written all over it. Ultimately then, though maybe indirectly, it points to the first Passover. Then it brings us through the first Passover to the last, the final shedding of blood for sin in the “cutting” of the Lamb, the Son of God, the Messiah.
One more interesting interpretation – another plausible one, perhaps even complementary – is how Moses represents Israel. Moses really pre-lives Israel’s journey, from a birth-deliverance through water to Mount Sinai in the wilderness, to this episode of Yahweh being angry with a recalcitrant child. More specifically, in Fretheim’s terms, “Just as Moses was saved by the blood of his firstborn, so Israel would be saved by the blood of the Egyptian firstborn” (Exodus, p. 80). In Isaiah’s terms, “I give Egypt as your ransom (kofer)” (43.3). As still one more interesting side note, a few verses before this episode, Yahweh calls Israel his firstborn and declares that he will cut off Egypt’s firstborn to save his. Yahweh’s sermon before this instance of the bloody briedgroom should help contextually interpret it.
This is just one tiny step forward in discussing this difficult text while noting and summarizing the scholarly positions. Again, see the above named authors for more detailed information. My presuppositions are akin to Enns’: the fact that Christ has risen from the dead profoundly affects our interpretation of the OT (Exodus, 26). In other words, there are glimmers, shadows, types, symbols, events, prophecies, hints, and arrows in the OT that bring us to the cross, empty tomb, and session of the Messiah. In Jesus’ own terms, Moses wrote about me.