כֹּ֣ה ׀ אָמַ֣ר יְהוָ֗ה מִנְעִ֤י קוֹלֵךְ֙ מִבֶּ֔כִי וְעֵינַ֖יִךְ מִדִּמְעָ֑ה כִּי֩ יֵ֨שׁ שָׂכָ֤ר לִפְעֻלָּתֵךְ֙ נְאֻם־יְהוָ֔ה וְשָׁ֖בוּ מֵאֶ֥רֶץ אוֹיֵֽב׃
Thus saith the LORD: Refrain thy voice from weeping, And thine eyes from tears; For thy work shall be rewarded, saith the LORD; And they shall come back from the land of the enemy.
Read kabbalistic (mystical) interpretation of Jeremiah 31:16: and classical mystical sources.