In Sunnī Islām, the Hadith of Gabriel (ḥadīth Jibrīl) is the single most important Hadīth (report on the words and actions of Muhammad). Its narrative contains the best summary of the core of Islam: the "Five Pillars of Islam", the "Six Articles of Faith", and Ihsan, or "doing what is beautiful". This Hadīth is found in both the Ṣaḥīḥ al-Bukhārī and the Ṣaḥīḥ Muslim. The hadith is known to express the religion of Islam in a nutshell.
Muslim scholars named this hadith the Hadith of Gabriel, because it is a narration from a companion (Sahaba) not from Muhammad, but from Gabriel. It is also one of those unique hadith where the Archangel Gabriel assumed human form and manifested himself before not only Muhammad but also his companions.
Hadith of Gabriel Wikipedia
Narrated by Abu Huraira:
One day while the Prophet was sitting in the company of some people, (The angel) Gabriel came and asked, "What is faith?" Allah's Messenger replied, 'Faith is to believe in Allah, His angels, (the) meeting with Him, His Apostles, and to believe in Resurrection." Then he further asked, "What is Islam?" Allah's Messenger replied, "To worship Allah Alone and none else, to offer prayers perfectly to pay the compulsory charity (Zakat) and to observe fasts during the month of Ramadan." Then he further asked, "What is Ihsan (perfection)?" Allah's Messenger replied, "To worship Allah as if you see Him, and if you cannot achieve this state of devotion then you must consider that He is looking at you." Then he further asked, "When will the Hour be established?" Allah's Messenger replied, "The answerer has no better knowledge than the questioner. But I will inform you about its portents.
- When a slave (lady) gives birth to her master.
- When the shepherds of black camels start boasting and competing with others in the construction of higher buildings. And the Hour is one of five things which nobody knows except Allah.
The Prophet then recited: "Verily, with Allah (Alone) is the knowledge of the Hour--." (31. 34) Then that man (Gabriel) left and the Prophet asked his companions to call him back, but they could not see him. Then the Prophet said, "That was Gabriel who came to teach the people their religion." Abu 'Abdullah said: He (the Prophet) considered all that as a part of faith.
Also from 'Umar, there is that he said, "While we were sitting with the Messenger of Allah, may Allah bless with him and grant him peace, one day a man came up to us whose clothes were extremely white, whose hair was extremely black, upon whom traces of travelling could not be seen, and whom none of us knew, until he sat down close to the Prophet, may Allah bless with him and grant him peace, so that he rested his knees upon his knees and placed his two hands upon his thighs and said, 'Muhammad, tell me about Islam.' The Messenger of Allah, may Allah bless with him and grant him peace, said, 'Islam is that you witness that there is no god but Allah and that Muhammad is the Messenger of Allah, and you establish the prayer, and you give the Zakat, and you fast Ramadan, and you perform the hajj of the House if you are able to take a way to it.' He said, 'You have told the truth,' and we were amazed at him asking him and [then] telling him that he told the truth. He said, 'Tell me about iman.' He said, 'That you affirm Allah, His angels, His books, His messengers, and the Last Day, and that you affirm the Decree, the good of it and the bad of it.' He said, 'You have told the truth.' He said, 'Tell me about ihsan.' He said, 'That you worship Allah as if you see Him, for if you don't see Him then truly He sees you.' He said, 'Tell me about the Hour.' He said, 'The one asked about it knows no more than the one asking.' He said, 'Then tell me about its tokens.' He said, 'That the female slave should give birth to her mistress, and you see poor, naked, barefoot shepherds of sheep and goats competing in making tall buildings.' He went away, and I remained some time. Then he asked, 'Umar, do you know who the questioner was?' I said, 'Allah and His Messenger know best.' He said, 'He was Jibril who came to you to teach you your deen'." Muslim (8) narrated it.