Psalms 89:35 Kabbalah

לֹא־אֲחַלֵּ֥ל בְּרִיתִ֑י וּמוֹצָ֥א שְׂ֝פָתַ֗י לֹ֣א אֲשַׁנֶּֽה׃

My covenant will I not profane, Nor alter that which is gone out of My lips.

Read kabbalistic (mystical) interpretation of Psalms 89:35: and classical mystical sources.