Mu'adh bin Anas Al-Juhani (May Allah be pleased with him) said:
The Prophet (ﷺ) forbade (us) from sitting with our legs drawn up to our belly (Ihtiba') during the Friday Khutbah (religious talk before the prayer).[Abu Dawud and At-Tirmidhi]. (DE)
App reference (DE): Book 18, Hadith 195 (DE)
Arabic/English book reference (DE): Book 18, Hadith 1705 (DE)