Pagan gobbledygook!I found this brief dictionary entry for the term "Immutability of God":
Absolute changelessness. That is mutable which goes from one condition to another. In consequence of its finite nature, every creature is mutable. God is unchangeable because he is infinite. Mutability implies potentiality, composition, and imperfection, and is therefore not reconcilable with God as pure actuality, the absolutely simple and infinitely perfect Being. When God acts outside of himself, as in the creation of the world, he does not produce a new effect in himself, but enters on a new realization of the eternal decision of his divine will. The decree of creation is as eternal and immutable as the Divine Essence with which it is really identical; only its effect, the created world, is temporal and changeable. (Etym. Latin immutabilis, unchangeable; changeless.)
https://www.catholicculture.org/culture/library/dictionary/index.cfm?id=34109
A thorough article on the subject is available here:
http://socrates58.blogspot.com/2009/01/catholic-dogmas-of-gods-immutability.html
Meaningless nonsense that is completely absent from the Bible.
Resting in Him,
Clete