“The Messenger of Allah (ﷺ) forbade Ihtiba’ (sitting with one's thighs gathered up against the stomach while wrapping one's arm or garment around them) on Fridays, meaning, when the Imam is delivering the sermon.”
Sunan Ibn Majah Book 5, Hadith 332
← Previous Hadith It was narrated from ‘Amr bin Shu’aib, from his father, from his grandfather, that the Messenger of Allah (ﷺ) forbade sitting in circles in the mosque on Fridays before the prayer.

Sunan Ibn Majah Book 5, Hadith 331 Next Hadith → “The Messenger of Allah (ﷺ) had only one Mu’adh-dhin. When he came out he would give the Adhan and when he came down (from the pulpit) he would give the Iqamah. Abu Bakr and ‘Umar did likewise, but when ‘Uthman (became caliph) the numbers of people had increased, he added the third call from atop a house in the marketplace that was called Zawra’. When he came out (the Mu’adh-dhin) would call the Adhan, and when he came down from the pulpit, he would call the Iqamah.

Sunan Ibn Majah Book 5, Hadith 333