The Book of Faith (Kitab Al-Iman)
Muslim :: Book 1 : Hadith 409
Abdullah b. al-Harith reported: I heard Abbas say: I said: Messenger of Allah, verily Abu Talib defended you and helped you; would it be beneficial for him? He (the Holy Prophet) said: Yes; I found him in the lowest part of the Fire and I brought him to the shallow part.