(35) باب فِي الْغَزْوِ مَعَ أَئِمَّةِ الْجَوْرِ
Narrated AbuHurayrah:
The Prophet (ﷺ) said: Striving in the path of Allah (jihad) is incumbent on you along with every ruler, whether he is pious or impious; the prayer is obligatory on you behind every believer, pious or impious, even if he commits grave sins; the (funeral) prayer is incumbent upon every Muslim, pious and impious, even if he commits major sins.
Reference: Sunan Abi Dawud 2533
In-book reference: Book 15, Hadith 57
English translation: Book 14, Hadith 2527