Psalms 87:1 Kabbalah

לִבְנֵי־קֹ֭רַח מִזְמ֣וֹר שִׁ֑יר יְ֝סוּדָת֗וֹ בְּהַרְרֵי־קֹֽדֶשׁ׃

A Psalm of the sons of Korah; a Song. His foundation is in the holy mountains.

Read kabbalistic (mystical) interpretation of Psalms 87:1: and classical mystical sources.