Volume 1, Book 12, Number 818:

Narrated Ibn 'Abbas:

One night I slept at the house of my aunt Maimuna and the Prophet slept (too). He got up (for prayer) in the last hours of the night and performed a light ablution from a hanging leather skin. ('Amr, the sub-narrator described that the ablution was very light). Then he stood up for prayer and I got up too and performed the ablution in the same way and joined him on his left side. He pulled me to the right and prayed as much as Allah will. Then he lay down and slept and I heard his breath sounds till the Mu'adh-dhin came to him to inform him about the (Fajr) prayer. He left with him for the prayer and prayed without repeating the ablution. (Sufyan the subnarrator said: We said to 'Amr, "Some people say, 'The eyes of the Prophet sleep but his heart never sleeps.' " 'Amr said, "'Ubai bin 'Umar said, 'The dreams of the Prophets are Divine Inspirations. Then he recited, '(O my son), I have seen in dream that I was slaughtering you (offering you in sacrifice).")

Volume 2, Book 21, Number 255:

Narrated Nafi:

Ibn 'Umar said, "In the life-time of the Prophet I dreamt that a piece of silk cloth was in my hand and it flew with me to whichever part of Paradise I wanted. I also saw as if two persons (i.e. angels) came to me and wanted to take me to Hell. Then an angel met us and told me not to be afraid. He then told them to leave me. Hafsa narrated one of my dreams to the Prophet and the Prophet said, "Abdullah is a good man. Would that he offer the night prayer (Tahajjud)!" So after that day 'Abdullah (bin 'Umar) started offering Tahajjud. The companions of the Prophet (p.b.u.h) used to tell him their dreams that (Laila-tul-Qadr) was on the 27th of the month of Ramadan. The Prophet said, "I see that your dreams agree on the last ten nights of Ramadan and so whoever is in search of it should seek it in the last ten nights of Ramadan."

Volume 3, Book 32, Number 232:

Narrated Ibn 'Umar:Some men amongst the companions of the Prophet were shown in their dreams that the night of Qadr was in the last seven nights of Ramadan. Allah's Apostle said, "It seems that all your dreams agree that (the Night of Qadr) is in the last seven nights, and whoever wants to search for it (i.e. the Night of Qadr) should search in the last seven (nights of Ramadan)."

Volume 6, Book 60, Number 480:

Narrated 'Aisha:

The commencement of (the Divine Inspirations to) Allah's Apostle was in the form of true dreams. The Angel came to him and said, "Read! In the Name of your Lord Who has created all exists), has created man from a clot. Read! And your Lord is Most Generous, Who has taught (the writing) by the pen (the first person to write was Prophet Idris).

Volume 7, Book 62, Number 15:

Narrated 'Aisha:

Allah's Apostle said (to me), "You have been shown to me twice in (my) dreams. A man was carrying you in a silken cloth and said to me, 'This is your wife.' I uncovered it; and behold, it was you. I said to myself, 'If this dream is from Allah, He will cause it to come true.' "

Volume 9, Book 87, Number 144:

Narrated Abu Huraira:

Allah's Apostle said, "When the Day of Resurrection approaches, the dreams of a believer will hardly fail to come true, and a dream of a believer is one of forty-six parts of prophetism, and whatever belongs to prothetism can never be false." Muhammad bin Sirin said, "But I say this." He said, "It used to be said, 'There are three types of dreams: The reflection of one's thoughts and experiences one has during wakefulness, what is suggested by Satan to frighten the dreamer, or glad tidings from Allah. So, if someone has a dream which he dislikes, he should not tell it to others, but get up and offer a prayer." He added, "He (Abu Huraira) hated to see a Ghul (i.e., iron collar around his neck in a dream) and people liked to see fetters (on their feet in a dream). The fetters on the feet symbolizes one's constant and firm adherence to religion." And Abu 'Abdullah said, "Ghuls (iron collars) are used only for necks."

Volume 9, Book 87, Number 155:

Narrated Ibn 'Umar:

Men from the companions of Allah's Apostle used to see dreams during the lifetime of Allah's Apostle and they used to narrate those dreams to Allah's Apostle. Allah's Apostle would interpret them as Allah wished. I was a young man and used to stay in the mosque before my wedlock. I said to myself, "If there were any good in myself, I too would see what these people see." So when I went to bed one night, I said, "O Allah! If you see any good in me, show me a good dream." So while I was in that state, there came to me (in a dream) two angels. In the hand of each of them, there was a mace of iron, and both of them were taking me to Hell, and I was between them, invoking Allah, "O Allah! I seek refuge with You from Hell." Then I saw myself being confronted by another angel holding a mace of iron in his hand. He said to me, "Do not be afraid, you will be an excellent man if you only pray more often." So they took me till they stopped me at the edge of Hell, and behold, it was built inside like a well and it had side posts like those of a well, and beside each post there was an angel carrying an iron mace. I saw therein many people hanging upside down with iron chains, and I recognized therein some men from the Quraish. Then (the angels) took me to the right side. I narrated this dream to (my sister) Hafsa and she told it to Allah's Apostle. Allah's Apostle said, "No doubt, 'Abdullah is a good man." (Nafi' said, "Since then 'Abdullah bin 'Umar used to pray much.)

Excerpted from the Sahih al-Bukhari