The students asked their teacher: "Master, you tell us — in what merit did the tribe of Judah attain kingship over Israel?" Rabbi Tarfon gave an answer that has echoed through Jewish tradition ever since. When the Israelites stood at the edge of the Red Sea with Pharaoh's army behind them, every tribe refused to go first. Each one said, "I will not go down into the water first." The prophet Hosea hints at this hesitation: "Ephraim has surrounded me with deceit" (Hosea 12:1) — a veiled reference to the tribes' reluctance at the critical moment.
While the others deliberated and delayed, one man acted. Nachshon the son of Aminadav, from the tribe of Judah, leapt straight into the waves of the sea. His entire tribe followed him. They did not wait for the waters to part. They did not demand guarantees. They plunged into a raging sea on nothing but faith.
This, Rabbi Tarfon explains, is why Judah merited kingship. The other tribes had faith in theory, but Nachshon had faith in practice. He was willing to drown for it. The Mekhilta teaches that leadership in Israel does not come from military strength or political cunning. It comes from the willingness to act when everyone else is frozen. Nachshon stepped into the impossible, and the sea responded by splitting before him. David's royal line descends from this single moment of radical courage.