The Messenger of Allah ﷺ said three times, "Religion is sincere counsel."It was asked, "Messenger of Allah, to whom?"He replied, "To Allah, to His Book, and to the leaders of the Muslims."
حدثني صفوان أخبرنا ابن عجلان عن القعقاع عن أبي صالح
قال رسول الله ﷺ الدين النصيحة ثلاث مرات قال قيل يا رسول الله لمن قال لله ولكتابه ولأئمة المسلمين
Its isnad is sahih. Tirmidhi (123) also related it from Bundar, who is Muhammad bin Bashshar, from Safwan bin Isa, with this same isnad. In his version the ending reads, "and for the leaders of the Muslims and their common people." He said, this is a hasan hadith.Its meaning has already appeared in the hadith of Ibn Abbas (3281), and Muslim related it from the hadith of Tamim Dari, and it is the seventh hadith of the Forty Hadith of Nawawi.Hafiz bin Rajab said in Jami al-Ulum wal-Hikam, this hadith was related by Muslim from the narration of Suhayl bin Abu Salih, from Ata bin Yazid Laythi, from Tamim Dari. It has also been narrated from Suhayl and others, from Abu Salih, from Abu Hurairah, from the Prophet, and Tirmidhi related it by this route. Some scholars judged it sahih from both routes together, while others said that the sahih hadith is that of Tamim, and the other isnad is a mistake.Tirmidhi related it only by the route through which Ahmad also related it, from the hadith of Qaqa, from Abu Salih, from Abu Hurairah. So if Suhayl bin Abu Salih also related it from his father, from Abu Hurairah, as Hafiz bin Rajab said, this would be a sahih corroboration of the narration of Qaqa from Abu Salih, and this would support the soundness of the hadith through both routes together, from the hadith of Abu Hurairah and from the hadith of Tamim Dari.