It is narrated from Sayyiduna Tamim al-Dari (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The religion is sincere goodwill (nasihah); the religion is sincere goodwill; the religion is sincere goodwill." The Companions said: To whom, O Messenger of Allah? He (peace and blessings be upon him) said: "To Allah, to His Book, to His Messenger, to the leaders of the Muslims, and to the believers in general."
Hadith Referenceالمعجم الكبير للطبراني / باب التاء / 1250