Sayyiduna Anas bin Malik (may Allah be pleased with him) reports this saying of the Prophet (peace and blessings be upon him): "Soon after me there will be sinful rulers who will offer the prayer outside its proper time. When they do that, offer the prayer at its proper time, and make your prayer with them a voluntary prayer."
Al-Tabarani recorded it in al-Awsat, and Abu Ya'la recorded it; its chain contains a narrator who could not be identified.
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب الصلاة / 1826