Tiferet Shlomo, on Festivals, Pesach 80תפארת שלמה, על הזמנים ומועדים, רמזי פסח פ׳
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Shemot Rabbah 22:3שמות רבה כ״ב:ג׳
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Shemot Rabbah 23:15שמות רבה כ״ג:ט״ו
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Perek Shirah, Introductory Text 1פרק שירה, הקדמה א׳
Rabbi Eliezer said: Anyone who involves himself with Perek Shirah in this world, merits saying it in the World-to-Come, as it says, “Then Moshe will sing”; it does not say “sang,” but “will sing” in the World-to-Come.