عَنْ أَبِي هُرَيْرَةَ ـ رضى اللّٰهُ عنه ـ أَنَّ رَسُولَ اللّٰه صَلَّى اللّٰهُ عَلَيْهِ وَسَلَّم كَانَ يَوْمًا بَارِزًا لِلنَّاسِ إِذْ أَتَاهُ رَجُلٌ يَمْشِي فَقَالَ يَا رَسُولَ اللّٰه مَا الإِيمَانُ قَالَ الإِيمَانُ أَنْ تُؤْمِنَ بِاللّٰه وَمَلاَئِكَتِهِ وَرُسُلِهِ وَلِقَائِهِ وَتُؤْمِنَ بِالْبَعْثِ الآخِرِ. قَالَ يَا رَسُولَ اللّٰه مَا الإِسْلاَمُ قَالَ الإِسْلاَمُ أَنْ تَعْبُدَ اللّٰه وَلاَ تُشْرِكَ بِهِ شَيْئًا، وَتُقِيمَ الصَّلاَةَ، وَتُؤْتِيَ الزَّكَاةَ الْمَفْرُوضَةَ، وَتَصُومَ رَمَضَانَ. قَالَ يَا رَسُولَ اللّٰه، مَا الإِحْسَانُ قَالَ الإِحْسَانُ أَنْ تَعْبُدَ اللّٰه كَأَنَّكَ تَرَاهُ، فَإِنْ لَمْ تَكُنْ تَرَاهُ فَإِنَّهُ يَرَاكَ. قَالَ يَا رَسُولَ اللّٰه مَتَى السَّاعَةُ قَالَ مَا الْمَسْئُولُ عَنْهَا بِأَعْلَمَ مِنَ السَّائِلِ، وَلَكِنْ سَأُحَدِّثُكَ عَنْ أَشْرَاطِهَا إِذَا وَلَدَتِ الْمَرْأَةُ رَبَّتَهَا، فَذَاكَ مِنْ أَشْرَاطِهَا، وَإِذَا كَانَ الْحُفَاةُ الْعُرَاةُ رُءُوسَ النَّاسِ فَذَاكَ مِنْ أَشْرَاطِهَا فِي خَمْسٍ لا يَعْلَمُهُنَّ إِلاَّ اللّٰه {إِنَّ اللّٰه عِنْدَهُ عِلْمُ السَّاعَةِ وَيُنَزِّلُ الْغَيْثَ وَيَعْلَمُ مَا فِي الأَرْحَامِ}. ثُمَّ انْصَرَفَ الرَّجُلُ فَقَالَ رُدُّوا عَلَىَّ. فَأَخَذُوا لِيَرُدُّوا فَلَمْ يَرَوْا شَيْئًا. فَقَالَ هَذَا جِبْرِيلُ جَاءَ لِيُعَلِّمَ النَّاسَ دِينَهُمْ.
Hazrat Abu Hurairahra narrated, “One day, as Allah’s Messengersa was sitting amongst the people, a man approached walking and asked, ‘O Messengersa of Allah, what is faith [iman]?’ The Prophetsa replied, ‘Faith is to believe in Allah, His angels, His books, His messengers, and in meeting Him, and to believe in the Final Resurrection.’ The man asked, ‘O Messengersa of Allah, what is Islam?’ The Prophetsa answered, ‘Islam is to worship Allah alone and associate none with Him, to observe prayers [salat], to give the obligatory charity [zakat], and to fast during Ramadan.’ The man then enquired, ‘O Messengersa of Allah, what is ihsan?’ The Prophetsa responded, ‘Ihsan is to worship Allah as though you see Him, and if you do not see Him, then truly He sees you.’ The man further asked, ‘O Messengersa of Allah, when will the Hour be established?’ The Prophetsa said, ‘The one questioned about it knows no more than the questioner. However, I will tell you about its signs. When a slave woman gives birth to her mistress, that is one of its signs. When the barefooted, naked people become the leaders of the people, that is one of its signs. The Hour is among five things known only to Allah.’ The Prophetsa then recited, ‘Verily, with Allah alone is the knowledge of the Hour. And He sends down the rain, and He knows what is in the wombs.’ (Holy Quran 31:35) After this, the man left. The Prophetsa said, ‘Call him back to me.’ When they went to call him back, they saw nothing. The Prophetsa remarked, ‘That was Gabriel who came to teach people their religion.’”
(Sahih al-Bukhari, Kitab at-tafsir, Bab qawlihi innallaha ‘indahu ‘ilmu s-sa‘ah, Hadith 4777)