וְעָֽרְבָה֙ לַֽיהוָ֔ה מִנְחַ֥ת יְהוּדָ֖ה וִירֽוּשָׁלִָ֑ם כִּימֵ֣י עוֹלָ֔ם וּכְשָׁנִ֖ים קַדְמֹנִיּֽוֹת׃
Then shall the offering of Judah and Jerusalem be pleasant unto the LORD, as in the days of old, and as in ancient years.
Read kabbalistic (mystical) interpretation of Malachi 3:4: and classical mystical sources.