The Song at the Sea begins with a grammatical mystery. The Hebrew text of (Exodus 15:1) reads az yashir Mosheh—literally, "then Moses will sing," using the future tense. If the Torah were simply describing a past event, it should have said az shar Mosheh—"then Moses sang." The Mekhilta seizes on this oddity and draws from it one of the most dramatic theological claims in all of rabbinic literature.
"It is not written 'Then Moses sang,'" the Mekhilta declares, "but 'then Moses will sing'—from here we derive the resurrection of the dead from Scripture."
The logic is striking. If the Torah uses the future tense to describe the Song at the Sea, it must be pointing forward—not just to that moment of triumph at the shores of the Red Sea, but to a future moment when Moses will sing again. And when will Moses sing again? At the resurrection of the dead, when all the righteous will rise and praise God once more.
This teaching became one of the foundational proof texts for the rabbinic belief in techiyat ha-metim, the resurrection. The Mishnah (the earliest code of rabbinic law) in Sanhedrin (10:1) famously declares that anyone who denies the resurrection has no share in the World to Come, and one of the key proofs cited is precisely this verse—the future tense of yashir.
For the rabbis, the Song at the Sea was never just a hymn of gratitude for a past deliverance. It was a prophecy encoded in grammar. Moses sang at the sea, and Moses will sing again—when the dead rise, when history reaches its culmination, and when the ultimate song of redemption echoes across a renewed world.