God is the "first cause" of reality.
Everything that exists was created and is affected by another force to which it owes its being and motive power-but God is the beginning of all, the First Cause, the initial Source.
God is preceded by nothing.
God's Being is the ultimate beginning.
–Rabbi Adin Steinsaltz
From The Thirteen Petalled Rose, Chapter 13,"Patach Eliyahu-Elijah Began," by Rabbi Adin Steinsaltz