Hadith 1705 - Bab 312 (Undesirability of Sitting with Erected Legs during Friday Sermon)
Chapter 18 (The Book of the Prohibited actions)

Mu'adh bin Anas Al-Juhani (May Allah be pleased with him) said: The Prophet (Peace be upon him) 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].

Selon Mou"àdh Ibn Anas Al Jouhanni (das), le Prophète (bsdl) a inter dit de s"asseoir en serrant ses genoux contre son ventre le vendredi alors que l"Imam prononce son sermon. (Rapporté par Abou Dawûd et Attirmidhi)