Sayyiduna Qabisah bin Waqqas (may Allah be pleased with him) said: The Messenger of Allah (peace and blessings be upon him) said: "After me there will be rulers over you who will delay the prayers. The prayer will be (a reward) for you and (a sin) against them. So keep praying with them as long as they lead you in prayer facing the Qiblah."
Hadith Referenceالمعجم الكبير للطبراني / باب القاف / 16049