Albert Barnes Commentary Isaiah 46:9

"Remember the former things of old: for I am God, and there is none else; [I am] God, and there is none like me;" — Isaiah 46:9 (ASV)

Remember the former things ... - Bear in mind the repeated and constant proofs that have been given that Yahweh is the true God—the proofs derived from the prediction of future events, and from the frequent interpositions of his providence on your behalf as a nation.

For I am God - (See the notes at Isaiah 44:6).