Abu Hurairah reported,

One day the Prophet ﷺ was sitting out in the open among the people when Jibreel came to him and asked, "What is faith?"The Prophet ﷺ replied, "Faith is that you believe in Allah, His angels, His Book, the meeting with Him, and His messengers, and that you believe in the resurrection."Jibreel asked, "What is Islam?"He replied, "Islam is that you worship Allah and associate nothing with Him, that you establish the prayer, pay the obligatory zakat, and fast Ramadan."Jibreel asked, "What is excellence?"He replied, "That you worship Allah as though you see Him, for even if you do not see Him, He surely sees you."Jibreel asked, "When is the Hour?"He replied, "The one asked about it knows no more than the one asking. But I will tell you of its signs. When a slave woman gives birth to her master, and when the herders of black camels compete with one another in raising tall buildings. It is among five things that none knows but Allah."Then the Prophet ﷺ recited, "Indeed, with Allah is knowledge of the Hour" [Luqman 31:34], to the end of the verse.Then the man turned to leave, and the Prophet ﷺ said, "Bring him back." But they could see no one. So he said, "That was Jibreel. He came to teach the people their religion."

عن أبي هريرة قال

كان النبي ﷺ بارزا يوما للناس، فأتاه جبريل، فقال: ما الإيمان؟ قال: الإيمان أن تؤمن بالله وملائكته وكتابه ولقائه ورسله وتؤمن بالبعث قال: ما الإسلام؟ قال: الإسلام أن تعبد الله ولا تشرك به، وتقيم الصلاة، وتؤدي الزكاة المفروضة، وتصوم رمضان قال: ما الإحسان؟ قال: أن تعبد الله كأنك تراه، فإن لم تكن تراه فإنه يراك. قال: متى الساعة؟ قال: ما المسئول عنها بأعلم من السائل، وسأخبرك عن أشراطها: إذا ولدت الأمة ربها، وإذا تطاول رعاة الإبل البهم في البنيان، في خمس لا يعلمهن إلا الله، ثم تلا النبي ﷺ: {إن الله عنده علم الساعة}[سورة لقمان: ٣٤]، الآية ثم أدبر، فقال: ردوه، فلم يروا شيئا، فقال: هذا جبريل، جاء يعلم الناس دينهم.