12 I have revealed and saved and proclaimed— I, and not some foreign god among you. You are my witnesses,” declares the LORD, “that I am God.

Read Isaiah 43:12 Using Other Translations

I have declared, and have saved, and I have shewed, when there was no strange god among you: therefore ye are my witnesses, saith the LORD, that I am God.
I declared and saved and proclaimed, when there was no strange god among you; and you are my witnesses," declares the LORD, "and I am God.
First I predicted your rescue, then I saved you and proclaimed it to the world. No foreign god has ever done this. You are witnesses that I am the only God,” says the LORD .