‘A’isha reported God’s Messenger as saying, “When God has a good purpose for a ruler He appoints for him a sincere minister who reminds him if he forgets and helps him if he remembers; but when God has a different purpose from that for him He appoints for him an evil minister who does not remind him if he forgets and does not help him if he remembers.”
Abu Sa'id reported God’s Messenger as saying, “The one who will be dearest to God and nearest to Him in station of the day of resurrection will be a just imam, and the one who will be most hateful to God on the day of resurrection and will receive the severest punishment (or as a version has, will be farthest from Him in station) will be a tyrannical imam.”
Tirmidhi transmitted it, saying this is a hasan gharib tradition.