Musannaf Ibn Abi Shayba 23:57

Abu Usama narrated to us, from al-A’mash, from Jami’ ibn Shaddad, from al-Aswad ibn Hilal, who said: Mu’adh used to say to a man among his brothers: "Sit with us so that we may believe for an hour." So they would sit and remember Allah and praise Him.