Surah 21. Al-Anbiya, Ayah 65

Lit., "they were turned upside down upon their heads": an idiomatic phrase denoting a "mental somersault" - in this case, a sudden reversal of their readiness to exonerate Abraham and a return to their former suspicion.

Literally, "they were turned down on their heads" which may suggest a metaphorical somersault, i.e., they recovered from their dawning shame for idolatry and were prepared to argue it out with the youth Abraham. But I think there is better authority for the interpretation I have adopted.