I heard the Messenger of Allah ﷺ say, "Even if a slave is appointed over you who leads you by the Book of Allah , listen to him and obey."
قال حدثنا يحيى بن سعيد عن شعبة قال حدثنا
سمعت رسول الله ﷺ يقول ولو استعمل عليكم عبد يقودكم بكتاب الله عز وجل فاسمعوا له وأطيعوا
Its isnad is sahih. Yahya bin Husayn bin Urwa Ahmasi was deemed reliable by Ibn Hibban, and Abu Hatim said, "Truthful." The hadith has already appeared in similar form at 12065, and it is found in Muslim 3/1468, no. 1838, and in similar form in Bukhari 13/121, no. 7142 (Fath).