Tafsir of Al-Anbiya' 21:56

"He said, 'Nay, your Lord...'"

The pronoun in {He who created them} refers to the heavens and the earth, or to the idols. That it refers to the idols is more fitting for their misguidance and more established for the purpose of arguing against them.

His testimony regarding this is his presentation of the argument against them, and his validation of it—just as a claim is validated by evidence. It is as if he said: "I clarify this and provide proof for it, just as claims are clarified by evidence, for I am not like you; I do not say what I cannot prove with an argument, whereas you were unable to provide an argument for your doctrine, and you did nothing more than find your forefathers following it."

{And by Allah, I will surely plot against your idols after you have turned and gone away. So he made them into fragments, except for a large one among them, that they might return to it.}