Sunan an-Nasa'i 4991

It was narrated that Abu Hurairah and Abu Dharr said:

"The Messenger of Allah [SAW] would sit among his Companions and if a stranger came, he would not know which of them was he (the Prophet [SAW]) until he asked. So we suggested to the Messenger of Allah [SAW] that we should make a dais for him so that any stranger would know him if he came to him. So we built for him a bench made of clay on which he used to sit. (One day) we were sitting and the Messenger of Allah [SAW] was sitting in his spot, when a man came along who was the most handsome and good-smelling of all people, and it was as if no dirt had ever touched his garments. He came near the edge of the rug and greeted him, saying: 'Peace be upon you, O Muhammad!' He returned the greeting, and he said: 'Shall I come closer, O Muhammad?' He came a little closer, and he kept telling him to come closer, until he put his hands on the knees of the Messenger of Allah [SAW]. He said: 'O Muhammad, tell me, what is Islam?' He said: 'Islam means to worship Allah and not associate anything with Him; to establish Salah, to pay Zakah, to perform Hajj to the House, and to fast Ramadan.' He said: 'If I do that, will I have submitted (be a Muslim)?' He said: 'Yes.' He said: 'You have spoken the truth,' we found it odd. He said: 'O Muhammad, tell me, what is faith?' He said: 'To believe in Allah [SWT], His Angels, the Book, the Prophets, and to believe in the Divine Decree.' He said: 'If I do that, will I have believed?' The Messenger of Allah [SAW] said: 'Yes.' He said: 'You have spoken the truth.' He said: 'O Muhammad, tell me, what is Al-Ihsan?' He said: 'To worship Allah [SWT] as if you can see Him, for although you cannot see Him, He can see you.' He said: 'You have spoken the truth.' He said: 'O Muhammad, tell me about the Hour.' He lowered his head and did not answer. Then he repeated the question, and he did not answer. Then he repeated the question (a third time) and he did not answer. Then he raised his head and said: 'The one who is being asked does not know more than the one who is asking. But it has signs, by which it may be known. When you see the herdsmen competing in building tall buildings, when you see the barefoot and naked ruling the Earth, when you see a woman giving birth to her mistress. Five things which no one knows except Allah [SWT]. Verily, Allah, with Him (alone) is the knowledge of the Hour up to His saying: 'Verily, Allah is All-Knower, All-Aware (of things).' Then he said: 'No, by the One who sent Muhammad with the truth, with guidance and glad tidings, I did not know him more than any man among you. That was Jibril, peace be upon you, who came down in the form of Dihyah Al-Kalbi.'"