Sahih Muslim Book 31, Hadith Number 6057.

Ibn ‘Umar reported that when a person saw anything in sleep during the lifetime of Allah’s Messenger (may peace he upon him) he narrated it to Allah’s Messenger, and I also had a longing that I should also see in a dream something which I should narrate to Allah’s Apostle (may peace be upon him) and I was at that time an unmarried young man. I was sleeping in the mosque during the lifetime of Allah’s Messenger (may peace be upon him) that I saw in a dream as if two Angels have taken hold of me and they have carried me to the fire, and, lo, it was built like the easing of a well and had two pillars like those of a well; and, lo, there were people in it whom I knew and I cried out: I seek refuge with Allah from Hell-fire; I seek refuge with Allah from Hell-fire. Then another Angel joined the two others, and said unto me: You need not fear I narrated this dream to liafsa and she narrated it to Allah’s Messenger, whereupon Allah’s Apostle said: Worthy is this man Abdullah, O that he would pray at night, and Silim added that Abdullah afterwards slept only but for a small part of the night.