The Messenger of Allah ﷺ prohibited to sit on hips by erecting feet, sticking them to the stomach and holding them with hands on Friday while the imam is delivering the sermon. (Using translation from Abū Dāʾūd 1110)
عَنْ رَسُولِ اللهِ ﷺ أَنَّهُ نَهَى عَنِ الْحُبْوَةِ يَوْمَ الْجُمُعَةِ وَالْإِمَامُ يَخْطُبُ