Abu Dawud Book 8, Hadith Number 2527.

Narated By AbuHurayrah : The Prophet (PBUH) 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.