I am God. — The first predicate is El, the mighty and strong one, the second Elohim, the one true object of worship. The verse that follows asserts what in modern language would be called the omniscience and the omnipotence of God.
Related Commentaries of Isaiah 46:9
Isaiah 46:9
9 Remember the former things of old: for I am God, and there is none else; I am God, and there is none like me,