Behold, God is great, and we know him not, neither can the number of his years be searched out. God is great - He is omnipotent.
We know him not - He is unsearchable.
Neither can the number of his years be searched out - He is eternal.
These three propositions are an ample foundation for endless disquisition. As to paraphrase and comment, they need none in this place; they are too profound, comprehensive, and sublime.