Zipporah at the inn

The ambiguous or fragmentary nature of the verses leaves much room for extrapolation, and rabbinical scholarship has provided a number of explanations. The earliest Jewish interpretations almost unanimously infer that Moses failed to circumcise his son, thereby angering God and provoking the attack, but Zipporah's quick action in circumcising her son appeases God and ends the confrontation.[2] The Talmud understands this episode to underscore the primacy of the biblical command for fathers to promptly circumcise their sons (either on the eighth day or at the first opportunity thereafter), such that even someone of Moses's accrued merit and stature was not exempt from punishment by death for delaying his son's circumcision even briefly.[3]

While the passage is frequently interpreted as referring to Gershom, Moses's firstborn, being circumcised, Rashi, citing the Midrash Exodus Rabbah, states that the passage instead refers to Eliezer, Moses's other son.[4]

The Targum Neophyti, a medieval midrashic translation of the Pentateuch into Aramaic, expands Zipporah's enigmatic "you are truly a bridegroom of blood" to "How beloved is the blood that has delivered this bridegroom from the hand of the Angel of Death."[5]

The question of how Moses, of all people, could have neglected to have his son circumcised and thus incurred the wrath of Hashem (God) was debated in classical Jewish scholarship. Rabbi El'azar ha-Moda'i argues that Jethro had placed an additional condition on the marriage between his daughter and Moses—that their firstborn son would be given over to idolatry and thus explaining why Moses was viewed negatively by Hashem.[6] One Midrashic interpretation is that, while Hashem allowed Moses to put off circumcising his son until they reached Egypt, rather than weaken him before the journey, Moses did not hasten to perform the task as soon as possible after he had arrived.[7]

Rabbinical commentators have asked how Zipporah knew that the act of circumcising her son would save her husband. Rashi, citing Talmudic and Midrashic sources, explains that the angel of God (which the Talmud, Nedarim 32a identifies as either Af and Hemah, the personifications of anger and fury), in the shape of a serpent, had swallowed Moses up to, but not including, his genitals, and that Zipporah therefore understood that this had happened on account of the delay in circumcising her son.[8][9] Haberman (2003), connecting this episode to the story of Eve and the serpent, argues that Zipporah immediately understood that the threat was related to circumcision by a "psychoanalytic link" between Moses's penis and his son's, the ambiguous use of pronouns taken as indicating the fundamental identity of the deity, her husband and her son in the woman's subconscious.[9]

The Samaritan Pentateuch differs from the Jewish Masoretic Text in many details. According to the Samaritan version of this episode, Zipporah took a sharp flint and cut herself as a physical sign of repentance, because she realized that God was angry at Moses for bringing her and their two sons along on the divine mission to free the Israelites from bondage in Egypt. In an attempt to demonstrate her repentance and prove herself worthy of joining her husband. This different narrative arises from the voweling of the Hebrew root word בנה (b-n-h). Whereas the Masoretic version states the Zipporah circumcised "her son" ("b'nah"; בְּנָהּ), the Samaritan text describes her as having circumcised "her understanding" or "her blocked heart" ("binnah"; בִּנָּהּ, Samaritan alphabet: ࠁࠪࠍ࠙ࠣࠄ ).[10] Moses saw Zipporah's act of self-mutilation as a remnant of his wife's idolatrous upbringing, and a demonstration that God's displeasure at her presence was indeed well-founded. Therefore, Moses sent Zipporah and their two sons back to her family in Midian. This assuaged God's wrath and spared Moses's life. It was only after the parting of the Red Sea and the Israelites' miraculous escape from Egypt that Moses's father-in-law Jethro brought Zipporah and her sons to rejoin Moses at the Israelite camp in the desert.

Many biblical scholars consider the passage fragmentary.

James Kugel (1998) suggests that the point of the episode is the explanation of the expression "bridegroom of blood" חתן דמים, apparently current in biblical times. The story would seem to illustrate that the phrase does not imply that a bridegroom should or may be circumcised at the time of his marriage, but that Moses by being bloodied by the foreskin of his son became a "bridegroom of blood" to Zipporah. The story has also been interpreted as emphasizing the point that the circumcision must be performed exactly at the prescribed time, as a delay was not granted even to Moses.[11]

German orientalist Walter Beltz thought that the original myth behind this story was about the right of Yahweh, as an ancient fertility god, to receive in sacrifice the first born son. He reasons that the pronouns cannot refer to Moses, since he is not mentioned in the text preceding the passage. Moreover, the preceding text speaks of Israel as Yahweh's first born son and that Yahweh would kill Pharaoh's first born son for not letting Israel out of Egypt. It is obvious, he concludes, that this leads the writer to insert this story about another first born son, Moses's. Accordingly, it can only mean that Yahweh wants to take possession of the son of Moses because he is entitled to the first-born male. The mother undertakes the circumcision, an ancient matriarchal relic, and touches Yahweh's genitals with the child's foreskin. Only this makes sense when she uses the marriage formula "you are my bridegroom of blood". For in doing so, she transfers the child of Moses into a marriage with Yahweh, making him a child of Yahweh. The complete sacrifice of the boy is replaced by the sacrifice of a part of the penis. The biblical redactor still bore this in mind when he added: "At that time she said 'bridegroom of blood,' referring to circumcision." Originally, young boys were sacrificed to the pantheistic Cretan and Phoenician goddesses only after the priestesses had consummated ritual intercourse, the sacred marriage, with them. Thus, some scholars argue this text comes from the same category as such practices.[12]

Meanwhile, William H. Propp argues that, assuming that this episode derives from the Jahwist ("J") source, links God's attack with Moses's killing of the Egyptian taskmaster (Ex. 2:11-12), which had not yet been expiated. Just as the paschal sacrifice would later on cause the Angel of Death to "pass over" the homes of the Hebrews, here the ritualistic spilling of his son's blood through circumcision atones for Moses's wrongdoing – "the bloodied child became a symbol of the paschal night, when the endangered first-born of Israel were saved by the blood of a lamb."[2]