Rabbi Elazar ben Azaryah made a bold claim about how deeply the Torah regards circumcision. The foreskin, he taught, is so repulsive in the eyes of God that Scripture uses "uncircumcised" as its ultimate term of condemnation for the wicked. To be called "uncircumcised" in the biblical idiom is not merely a physical description — it is a moral verdict.
His proof text is devastating. (Jeremiah 9:25) declares: "For all the nations are uncircumcised, and all the house of Israel is uncircumcised of heart." The prophet Jeremiah reaches for the most damning language he can find to condemn Israel's spiritual failures, and the word he chooses is "uncircumcised." Even Israel — who bears the physical sign of the covenant on their flesh — can be called uncircumcised when their hearts turn away from God.
Rabbi Elazar ben Azaryah is teaching that circumcision operates on two levels. The physical act of brit milah marks the body as belonging to the covenant. But the prophet reveals that a person can be physically circumcised and yet spiritually "uncircumcised of heart." The foreskin becomes a metaphor for anything that blocks a person's connection to God — stubbornness, idolatry, moral corruption.
The Mekhilta draws from this a powerful argument for the centrality of circumcision in Jewish identity. If the Torah and the prophets use "uncircumcised" as the worst thing you can call someone — worse than "wicked," worse than "rebellious" — then the covenant of circumcision must be among the most foundational commitments in all of Judaism. The foreskin shames the nations, and its spiritual equivalent shames even Israel.