Musannaf Ibn Abi Shayba 27:683

Ghundar narrated to us, from Shu'bah, from Simak, from Abdullah ibn Shaddad, that the Prophet (peace and blessings of Allah be upon him) said to Sa'd while he was struggling with his soul: "May Allah reward you with good on behalf of the leader of your people. You were truthful to Allah in what you promised Him, and He is truthful in what He promised you."