ثُمَّ نُكِسُوا عَلَىٰ رُءُوسِهِمْ لَقَدْ عَلِمْتَ مَا هَٰؤُلَاءِ يَنطِقُونَ ٦٥

Then they were turned upside down upon their heads (i.e., their thinking reverted and they said: ‘Ibrahim [Abraham]), surely you yourself know that they do not speak.’ (21:65)