Sahih Bukhari
Merits of the Helpers in Madinah (Ansaar)
Volume: 005 / Book Number: 058 / Hadith Number: 224
Narrated Abu Said Al-Khudri:
That he heard the Prophet when somebody mentioned his uncle (i.e. Abu Talib), saying, "Perhaps my intercession will be helpful to him on the Day of Resurrection so that he may be put in a shallow fire reaching only up to his ankles. His brain will boil from it."