Sahih al-Bukhari 4621
Narrated Anas:
The Prophet (ﷺ) delivered a sermon the like of which I had never heard before. He said, "If you but knew 
what I know then you would have laughed little and wept much." On hearing that, the companions of 
the Prophet (ﷺ) covered their faces and the sound of their weeping was heard. A man said, "Who is my 
father?" The Prophet (ﷺ) said, "So-and-so." So this Verse was revealed: "Ask not about things which, if 
made plain to you, may cause you trouble." (5.101)
حَدَّثَنَا مُنْذِرُ بْنُ الْوَلِيدِ بْنِ عَبْدِ الرَّحْمَنِ الْجَارُودِيُّ، حَدَّثَنَا أَبِي، حَدَّثَنَا شُعْبَةُ، عَنْ مُوسَى بْنِ أَنَسٍ، عَنْ أَنَسٍ ـ رضى الله عنه ـ قَالَ خَطَبَ رَسُولُ اللَّهِ صلى الله عليه وسلم خُطْبَةً مَا سَمِعْتُ مِثْلَهَا قَطُّ، قَالَ ‏"‏ لَوْ تَعْلَمُونَ مَا أَعْلَمُ لَضَحِكْتُمْ قَلِيلاً وَلَبَكَيْتُمْ كَثِيرًا ‏"‏‏.‏ قَالَ فَغَطَّى أَصْحَابُ رَسُولِ اللَّهِ صلى الله عليه وسلم وُجُوهَهُمْ لَهُمْ خَنِينٌ، فَقَالَ رَجُلٌ مَنْ أَبِي قَالَ فُلاَنٌ فَنَزَلَتْ هَذِهِ الآيَةُ ‏{‏لاَ تَسْأَلُوا عَنْ أَشْيَاءَ إِنْ تُبْدَ لَكُمْ تَسُؤْكُمْ‏}‏‏.‏ رَوَاهُ النَّضْرُ وَرَوْحُ بْنُ عُبَادَةَ عَنْ شُعْبَةَ‏.‏