The Mekhilta continues its grammatical investigation of the Song at the Sea and finds yet another future-tense verb. (Exodus 15:7) does not say "He has consumed them as stubble" — past tense — but "He will consume them as stubble," pointing unmistakably toward a future reckoning.
The proof texts are drawn from the prophets. (Obadiah 1:18) paints the picture in vivid terms: "The house of Jacob will be fire, and the house of Joseph, flame, and the house of Esau, stubble, and they will ignite them and consume them." Fire and flame against stubble — the outcome is inevitable. The house of Esau, representing the enemies of Israel, cannot withstand the blaze.
(Zechariah 12:6) adds another layer: "On that day I will make the chieftains of Judah like a stove — fire burning wood, a torch burning sheaf." The imagery escalates. Judah's leaders become the furnace itself, and everything opposed to them is reduced to ash.
This teaching from the Mekhilta DeRabbi Yishmael (Tractate Shirah 6:12) reads the drowning of Egypt as prologue. The stubble that the waters consumed at the Red Sea was merely the first batch. In the time to come, the fire of Jacob and Joseph will consume a far greater harvest. The Song at the Sea, the rabbis insist, is not only a song of memory — it is a song of prophecy.