Musannaf Ibn Abi Shayba 33:681

Abu Mu'awiyah narrated to us, from al-A'mash, who said: Sulaym ibn al-Aswad, Abu al-Sha'tha', entered upon Abu Wa'il to visit him. He said: "Indeed, in death there is rest." Abu Wa'il said: "I have a Companion who is better for me than you: five prayers in the day."