בַּעֲשׂוֹתְךָ֥ נוֹרָא֖וֹת לֹ֣א נְקַוֶּ֑ה יָרַ֕דְתָּ מִפָּנֶ֖יךָ הָרִ֥ים נָזֹֽלּוּ׃
when Thou didst tremendous things which we looked not for— Oh that Thou wouldest come down, that the mountains might quake at Thy presence!—
Read kabbalistic (mystical) interpretation of Isaiah 64:2: and classical mystical sources.