Musannaf Ibn Abi Shayba 3:2911

Ibn Fudayl narrated to us, from Abu Hayyan, from Hammad, who said: I said to Ibrahim, "Books come from the direction of Qutaybah containing falsehood and lies. So, when I want to speak to my companion, should I speak or remain silent?" He said, "No, rather remain silent," meaning during the Friday [prayer/sermon].