Tafsir of Al-Anbiya' 21:62

This is an example of ma‘arid al-kalam (allusive speech). The subtleties of this genre are only penetrated by the refined minds of scholars of rhetoric (‘ulama al-ma‘ani).

The explanation is that Ibrahim (peace be upon him) did not intend to attribute the act he performed to the idol. Rather, he intended to confirm it for himself and establish it as his own, using an allusive style to achieve his goal of compelling them with the argument and silencing them.

This is like a friend asking you—when you have written a document in elegant calligraphy and are famous for your beautiful handwriting—"Did you write this?" while your friend is illiterate, cannot write well, and is only capable of illegible scribbles. If you reply, "Rather, you wrote it," your intention in this answer is to confirm that you wrote it while mocking him, not to deny it from yourself or attribute it to the illiterate scribbler. Since the matter is between the two of you, attributing it to the incapable one is a form of mockery, and it serves to confirm it for the capable one.

It may also be said: Those idols enraged him when he saw them lined up and arranged, and the rage he felt toward the "greatest" one was greater and more intense because of the excessive veneration he saw them showing it. Thus, he attributed the act to it because it was the cause of his disdain for them and his smashing of them; for an act is attributed to the one who incites it just as it is attributed to the one who performs it.

It is also possible that his statement was a hypothetical concession to their own doctrine, as if he were saying to them: "What prevents you from believing that their 'greatest' one did it? For it is the right of one who is worshipped and claimed to be a god to be capable of this and even more."

It is narrated that he said: "Their greatest one did it; he became angry that these smaller ones were worshipped alongside him, while he is greater than them."

Muhammad ibn al-Sumayqa‘ read it as fa-la‘allahu kabiruhum (Perhaps their greatest one did it), meaning: "Perhaps the doer is their greatest one."