The 7th of the 42 hadiths gathered by Imam Yahya ibn Sharaf an-Nawawi in An-Nawawi's Forty Hadith, given below in the original Arabic with an English translation and its reference.
عَنْ أَبِي رُقَيَّةَ تَمِيمِ بْنِ أَوْسٍ الدَّارِيِّ رَضِيَ اللهُ عَنْهُ أَنَّ النَّبِيَّ صلى الله عليه وسلم قَالَ: "الدِّينُ النَّصِيحَةُ." قُلْنَا: لِمَنْ؟ قَالَ: "لِلَّهِ، وَلِكِتَابِهِ، وَلِرَسُولِهِ، وَلِأَئِمَّةِ الْمُسْلِمِينَ وَعَامَّتِهِمْ." [رَوَاهُ مُسْلِمٌ]
On the authority of Tameem ibn Aus ad-Daree (ra): The Prophet (ﷺ) said, “The deen (religion) is naseehah (advice, sincerity).” We said, “To whom?” He (ﷺ) said, “To Allah, His Book, His Messenger, and to the leaders of the Muslims and their common folk.” [Muslim]
Text from the open hadith-api dataset. Hadith numbering follows that edition and can differ slightly from a printed copy — check the Arabic against a trusted mushaf of hadith before relying on a reference.