Sahih Muslim
The Book Pertaining to Repentance and Exhortation to Repentance (Kitab Al-Tauba)
Book Number: 037 / Hadith Number: 6625
Hanzala Taimi Ufayyidi, the scribe of Allah's Messenger (may peace be upon him), reported: We were in the presence of Allah's Messenger (may peace be upon him) and he brought to our minds the problems pertaining to Paradise and Hell-Fire. The rest of the hadith is the same.