Tafsir of Al-Anbiya' 21:65

"Then they were turned upon their heads..."

• "Nakkastuhu" (نكسته): I turned it upside down, making its bottom its top.
• "Intakasa" (انتكس): He was turned over.

The meaning:

1. They had returned to their senses and arrived at a sound realization, but then they regressed and turned back from that state. They resumed arguing with falsehood and arrogance, claiming that these [idols]—despite being lower in status than a speaking animal—were deities to be worshipped, as a way of opposing him.
2. They turned back from being those who argued against Abraham (peace be upon him) to being those who argued on his behalf, at the moment they denied the idols the ability to speak.
3. They were literally turned upon their heads due to the intensity of their bowing their heads in shame, brokenness, and humiliation from the argument Abraham (peace be upon him) had used to stun them, leaving them unable to offer any response that could serve as a proof for them.

Variants: It is recited as nukkisu (نُكِّسوا) with a shadda, and nukisu (نُكِسوا), in the passive voice. This means they turned themselves upon their heads. This was recited by Ridwan ibn Abd al-Ma'bud.

"He said: 'Do you then worship, instead of Allah, that which does not benefit you at all, nor harm you? Fie upon you and upon what you worship instead of Allah! Do you not then use your reason?'"