It was narrated from Abu Hurairah that the Messenger of Allah said:"Religion is sincerity, religion is sincerity (Al-Nasihah), religion is sincerity." They said; "To whom, O Messenger of Allah?" He said: "To Allah, to His Book, to His Messenger, to the imams of the Muslims and to their common folk
Hadith No. 4199
Sunan an Nasai
Gradings:
Abu Ghuddah:
Hasan Sahih
Al-Albani:
Hasan Sahih
Zubair Ali Zai:
Sahih