Musnad Ahmad 941:77

Muhammad ibn Ja‘far narrated to us, Shu‘bah narrated to us, from Sulayman, who said: I heard Abu Wa’il say: It was said to Usamah: "Will you not speak to this man?" He said: "I have already spoken to him. I heard the Messenger of Allah (peace and blessings of Allah be upon him) say: 'A man will be brought and cast into the Fire, and he will be ground therein like a donkey grinding with its millstone. The people of the Fire will gather around him and say: "O so-and-so, were you not one who used to enjoin the good and forbid the evil?" He will say: "I used to enjoin the good but not do it, and I used to forbid the evil and do it."'" Shu‘bah said: And Mansur narrated to me, from Abu Wa’il, from Usamah, something similar to it, except that he added in it: "And the intestines of his belly will spill out."