Sahih Bukhari Volume 8, Book 77, Hadith Number 608.

Narated By Abu Said Al-Khudri : That the Prophet said, “No Caliph is appointed but has two groups of advisors: One group advises him to do good and urges him to adopt it, and the other group advises him to do bad and urges him to adopt it; and the protected is the one whom Allah protects.”