Sahih Muslim
The Book Giving Description of the Day of Judgement, Paradise and Hell (Kitab Sifat Al-Qiyamah wal Janna wan-Nar)
Book Number: 039 / Hadith Number: 6713
Abdullah reported: I was walking along with Allah's Apostle (may peace be upon him) in a field of Medina. The rest of the hadith is the same, but there is a slight variation of wording.