Sahih Bukhari Volume 9, Book 92, Hadith 7100

حَدَّثَنِي بِشْرُ بْنُ خَالِدٍ، أَخْبَرَنَا مُحَمَّدُ بْنُ جَعْفَرٍ، عَنْ شُعْبَةَ، عَنْ سُلَيْمَانَ، سَمِعْتُ أَبَا وَائِلٍ، قَالَ قِيلَ لأُسَامَةَ أَلاَ تُكَلِّمُ هَذَا‏.‏ قَالَ قَدْ كَلَّمْتُهُ مَا دُونَ أَنْ أَفْتَحَ بَابًا، أَكُونُ أَوَّلَ مَنْ يَفْتَحُهُ، وَمَا أَنَا بِالَّذِي أَقُولُ لِرَجُلٍ بَعْدَ أَنْ يَكُونَ أَمِيرًا عَلَى رَجُلَيْنِ أَنْتَ خَيْرٌ‏.‏ بَعْدَ مَا سَمِعْتُ مِنْ رَسُولِ اللَّهِ صلى الله عليه وسلم يَقُولُ ‏"‏ يُجَاءُ بِرَجُلٍ فَيُطْرَحُ فِي النَّارِ، فَيَطْحَنُ فِيهَا كَطَحْنِ الْحِمَارِ بِرَحَاهُ، فَيُطِيفُ بِهِ أَهْلُ النَّارِ فَيَقُولُونَ أَىْ فُلاَنُ أَلَسْتَ كُنْتَ تَأْمُرُ بِالْمَعْرُوفِ، وَتَنْهَى عَنِ الْمُنْكَرِ فَيَقُولُ إِنِّي كُنْتُ آمُرُ بِالْمَعْرُوفِ وَلاَ أَفْعَلُهُ، وَأَنْهَى عَنِ الْمُنْكَرِ وَأَفْعَلُهُ ‏"‏‏

Narrated By Abu Wail : Someone said to Usama, "Will you not talk to this (Uthman)?" Usama said, "I talked to him (secretly) without being the first man to open an evil door. I will never tell a ruler who rules over two men or more that he is good after I heard Allah's Apostle saying, 'A man will be brought and put in Hell (Fire) and he will circumambulate (go around and round) in Hell (Fire) like a donkey of a (flour) grinding mill, and all the people of Hell (Fire) will gather around him and will say to him, O so-and-so! Didn't you use to order others for good and forbid them from evil?' That man will say, 'I used to order others to do good but I myself never used to do it, and I used to forbid others from evil while I myself used to do evil.'"