Rabbi Yossi HaGlili presents one of the most famous calculations in rabbinic literature. He asks: how do we know that the Egyptians were struck with ten plagues in Egypt and fifty plagues at the sea? The proof hinges on two words — "finger" and "hand."
In Egypt, when the magicians failed to replicate the plague of lice, they told Pharaoh: "It is the finger of God" (Exodus 8:15). The plagues in Egypt were delivered by a single divine finger. At the Red Sea, however, the Torah uses a different word: "And Israel saw the great hand that the Lord used against Egypt" (Exodus 14:31). Not a finger — a hand.
The arithmetic is elegant. A hand has five fingers. If one finger produced ten plagues in Egypt, then a full hand at the sea produced five times ten — fifty plagues. The Egyptians suffered five times more punishment at the sea than they did during the entire course of the ten plagues in Egypt. What Israel experienced as ten devastating blows over the course of months in Egypt was multiplied fivefold and delivered all at once in the waters of the sea.
This calculation became so central to Jewish tradition that it was incorporated into the Passover Haggadah (non-legal rabbinic narrative), where subsequent rabbis expanded it even further — Rabbi Eliezer calculated two hundred plagues at the sea, and Rabbi Akiva reached two hundred and fifty. Rabbi Yossi HaGlili's original formula, however, remains the foundation: the sea was not merely a dramatic ending to the Exodus. It was the main event, dwarfing everything that came before it.