On the authority of Umar, radiyallahu'anhu, who said,
"While we were one day sitting with The Messenger of Allah, sallallahu'alayhi wassalam, there appeared before us a man dressed in extremely white clothes, and with very black hair. No traces of journeying were visible on him and none of us knew him.
He sat down close by the Prophet sallallahu'alayhi wassalam, rested his knee against his thighs, and said "O Muhammad! Inform me about Islam."
Messenger of Allah, sallallahu'alayhi wassalam, said, "Islam is that you should testify there is no god except Allah and that Muhammad is His Messenger, that you should perform salah, pay the zakat, fast during Ramadhan, and perform Hajj to the House, if you could find the way to it."
Said he (the man), "You have spoken the truth."
We were astonished at his questioning him and telling him that he was right, but he went on to say, "Inform me about Iman." He (The Messenger) answered "Is that you believe in Allah and His angels and His Books and His Messengers and in the Last Day, and in fate, both in its good and its evil aspects."
He said: You have spoken the truth.
Then he (the man) said, "Inform me about Ihsan."
He (The Messenger of Allah) answered, "It is that you should serve Allah as thought you could see Him, for thought you cannot see Him but He sees you."
The man said, "Inform me about The Hour."
He (The Messenger of Allah) said, "About that the one questioned knows no more than the questioner."
So he said, "Well inform me about the signs (of its coming)."
He (The Messenger of Allah) said, "They are that the slave-girl will give birth to her mistress, that you will see the bare-footed ones, the naked, the destitute, the herdsmen of the sheep (competing each other) in raising lofty buildings."
Thereupon the man went off.
I waited a while, and then he (The Messenger of Allah) said, "O 'Umar, do you know who that questioner was?"
I replied, "Allah and His Messenger know best."
He said, "That was Jibril. He came to teach to you your religion." "
Copied from a
video posted on the facebook.