Sunan an-Nasai Book 39, Hadith 4202

أَخْبَرَنَا يُونُسُ بْنُ عَبْدِ الأَعْلَى، قَالَ حَدَّثَنَا ابْنُ وَهْبٍ، قَالَ أَخْبَرَنِي يُونُسُ، عَنِ ابْنِ شِهَابٍ، عَنْ أَبِي سَلَمَةَ بْنِ عَبْدِ الرَّحْمَنِ، عَنْ أَبِي سَعِيدٍ، عَنْ رَسُولِ اللَّهِ صلى الله عليه وسلم قَالَ ‏ "‏ مَا بَعَثَ اللَّهُ مِنْ نَبِيٍّ وَلاَ اسْتَخْلَفَ مِنْ خَلِيفَةٍ إِلاَّ كَانَتْ لَهُ بِطَانَتَانِ بِطَانَةٌ تَأْمُرُهُ بِالْخَيْرِ وَبِطَانَةٌ تَأْمُرُهُ بِالشَّرِّ وَتَحُضُّهُ عَلَيْهِ وَالْمَعْصُومُ مَنْ عَصَمَ اللَّهُ عَزَّ وَجَلَّ ‏"‏ ‏.‏

It was narrated from Abu Saeed tht the Messenger of Allah said:"Allah never sends a prophet or appoints a Khalifah but he has two groups of advisers: A group that tells him to do good and a group that tells him to do evil and urges him to do it. And the one who is truly protected is the one who is protected by Allah, the Mighty and Sublime