Musannaf Ibn Abi Shayba 33:1206

Hussain bin Ali narrated to us, from Malik bin Mughul, who said: A man passed by Rabi’ bin Abi Rashid while he was sitting on one of the blacksmiths' chests. He said to him: "If only you would enter the mosque and sit with your brothers." Rabi’ said to him: "If the remembrance of death were to leave my heart for an hour, I fear that my heart would become corrupted."