It is reported that Abd Allah ibn Omar (ra) said that his father Omar (ra) said: One day, while we were with the Prophet (pbuh) a man, with shining white clothes and jet black hair, appeared before us. We could see no indications of a journey on him and neither did anyone among us know him [to be a resident of Medinah]. [He kept advancing towards us] till he sat himself in front of the Prophet (pbuh). [So close was he to the Prophet (pbuh) that] his knees touched the Prophet's knees; he placed his hands on his [own] legs. He asked: 'Muhammad, inform me about Islam'. The Prophet (pbuh) replied: 'Islam is that you bear witness that there is no god, except the One God and that Muhammad is the messenger of God; that you establish Sala'h; that you pay Zaka'h; that you fast during [the month of] Ramadan; and that you undertake the Hajj of the Bayet Allah, if you are in a position to do so'3. He said: 'You are right'. Omar said: 'We were surprised at him. He asked the Prophet a question and then himself verified the Prophet's answer'.
Then he said: 'Inform me about Iman'. The Prophet (pbuh) said: 'Iman is that you believe in God, His angels, His books, His prophets; the Final Day2 and that you believe that the desirable and the undesirable events [in life] are all from God'3. He said: 'You are right'.
Then he said: 'Inform me about Ihsan'. The Prophet replied: 'Ihsan is that you serve God as if He was right in front of your eyes; for even if you cannot see Him, He definitely sees you'4.
Then he said: 'Inform me about the Hour [when shall it happen?]' The Prophet (pbuh) replied: 'The person who is being asked is no more aware of it than the inquirer'.
Then he said: 'Tell me about its signs'. The Prophet (pbuh) replied: 'That the slave girl will give birth to the free woman; that you shall see these bare footed, naked, and poor shepherds [of Arabia] competing with each other in making high buildings'
Omar continued: Then he went away and I kept sitting there for quite some time. Then the Prophet (pbuh) said to me: 'Omar, do you know who this inquirer was?' I said: 'God and His messenger know best'. He said: 'It was Gabriel. He came to you to teach you [some important aspects of] your religion'.
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