Haggai 2:18 Kabbalah

שִׂימוּ־נָ֣א לְבַבְכֶ֔ם מִן־הַיּ֥וֹם הַזֶּ֖ה וָמָ֑עְלָה מִיּוֹם֩ עֶשְׂרִ֨ים וְאַרְבָּעָ֜ה לַתְּשִׁיעִ֗י לְמִן־הַיּ֛וֹם אֲשֶׁר־יֻסַּ֥ד הֵֽיכַל־יְהוָ֖ה שִׂ֥ימוּ לְבַבְכֶֽם׃

consider, I pray you, from this day and forward, from the four and twentieth day of the ninth month, even from the day that the foundation of the LORD’S temple was laid, consider it;

Read kabbalistic (mystical) interpretation of Haggai 2:18: and classical mystical sources.