תִּכָּ֣תֶב זֹ֭את לְד֣וֹר אַחֲר֑וֹן וְעַ֥ם נִ֝בְרָ֗א יְהַלֶּל־יָֽהּ׃
이 일이 장래 세대를 위하여 기록되리니 창조함을 받을 백성이 여호와를 찬송하리로다
Beit Aharon
It is found in the Midrash: "Write this for the last generation; and a nation will be created that will praise the Lord" (Psalms 102:19) - since the Holy One, blessed be He, creates them as a new creature on Rosh Hashanah and Yom Kippur. So what is incumbent upon us to do? To take a citron (etrog) and a lulav and praise Him.