When God commanded that a jar of manna be preserved, the instruction was specific (Exodus 16:33): "Put therein a full omer of manna and place it before the Lord as a keeping for your generations." But what did "for your generations" actually mean? Rabbi Yehoshua had a surprising answer: it meant "for the fathers"—that is, for the people of that specific generation who witnessed the miracle firsthand.
This interpretation cuts against the obvious reading. One would expect "for your generations" to mean for future generations—a memorial preserved so that children and grandchildren could see what their ancestors ate in the desert. And indeed, other rabbis read it exactly that way. Rabbi Eliezer taught that the preserved jar of manna was kept for the days of the prophet Jeremiah, who centuries later took it out to show the people of his generation as proof that God provides for those who study Torah.
But Rabbi Yehoshua's reading carries its own logic. The generation that left Egypt needed the memorial too. They needed a physical reminder of the miracle they were living through, because even people who experience wonders firsthand can forget them. The jar of manna placed before the Lord in the Tabernacle was not just a time capsule for the future. It was a daily testimony for the present—a visible, tangible proof sitting in the most sacred space in the Israelite camp.
The debate between Rabbi Yehoshua and Rabbi Eliezer reflects a deeper question about the nature of memory. Is sacred memory primarily for those who come after, or for those who lived it? The Mekhilta preserves both answers, suggesting that the jar of manna served both purposes—anchoring the past for those who experienced it and transmitting it forward to those who never would.