Sahih Muslim
The Book Pertaining to Paradise, Its Description, Its Bounties and Its Intimates (Kitab Al-Jannat wa Sifat Naimiha wa Ahliha)
Book Number: 040 / Hadith Number: 6816
Samura b. Jundub reported Allah's Messenger (may peace be upon him) as saying: There would be among them those to whom the fire will reach up to their ankels and to some of them the fire would reach their knees and to some it would reach their waists and to some it would reach up to their collar-bones.