לִבְּךָ֖ יֶהְגֶּ֣ה אֵימָ֑ה אַיֵּ֤ה סֹפֵר֙ אַיֵּ֣ה שֹׁקֵ֔ל אַיֵּ֖ה סֹפֵ֥ר אֶת־הַמִּגְדָּלִֽים׃
Thy heart shall muse on the terror: ‘Where is he that counted, where is he that weighed? Where is he that counted the towers?’
Read kabbalistic (mystical) interpretation of Isaiah 33:18: and classical mystical sources.