Sahih Bukhari Volume 005, Book 057, Hadith Number 083.

Narated By Ibn 'Umar : If a man saw a dream during the lifetime of the Prophet he would narrate it to the Prophet. Once I wished to see a dream and narrate it to the Prophet I was young, unmarried, and used to sleep in the Mosque during the lifetime of the Prophet. I dreamt that two angels took me and went away with me towards the (Hell) Fire which looked like a well with the inside walls built up, and had two side-walls like those of a well. There I saw some people in it whom I knew. I started saying, "I seek Refuge with Allah from the (Hell) Fire, I seek Refuge with Allah from the (Hell) Fire." Then another angel met the other two and said to me, "Do not be afraid." I narrated my dream to Hafsa who, in her turn, narrated it to the Prophet. He said, "What an excellent man Abdullah is if he only observes the night prayer." (Salem, a sub-narrator said, "Abdullah used not to sleep at night but very little hence forward."