Musnad Ahmad Hadith 21819

Abu Wa'il says that someone said to Usama (may Allah be pleased with him), "Why do you not speak to Uthman (may Allah be pleased with him)?" He replied, "Do you think that whatever I say to him, I will also tell you? Whatever I say to him is between me and him. I do not like to be the first to disclose this matter. And by Allah! I cannot say about any man that you are the best of all people, even if he is my ruler, while I have also heard the Prophet Muhammad (ﷺ) say regarding this that on the Day of Resurrection a man will be brought and thrown into Hell, and his intestines will come out, and he will go around with them as a donkey goes around a millstone. Seeing this, all the people of Hell will gather around him and say, 'O so-and-so! What has happened to you? Did you not command us to do good and forbid us from evil?' He will reply, 'I used to command you to do good, but I did not do it myself, and I used to forbid you from sins, but I used to do them myself.'"