Umm Salamah (may Allah be pleased with her), the wife of the Prophet (peace and blessings be upon him), narrates that the Messenger of Allah (peace and blessings be upon him) said: "Soon there will be rulers (imams) appointed over you; you will approve of some of what they do and disapprove of some. So whoever disapproves"
Sulayman said: Hisham said: "(disapproves) with his heart is free (of blame), and whoever dislikes it is safe; but (the blameworthy one) is he who is pleased and follows (them)." It was said: O Messenger of Allah, shall we not fight them? He (peace and blessings be upon him) said: "No, as long as they pray."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب صلاة الاستسقاء / 6503