Sahih Bukhari Volume 4, Book 59, Hadith 3207

حَدَّثَنَا مَكِّيُّ بْنُ إِبْرَاهِيمَ، حَدَّثَنَا ابْنُ جُرَيْجٍ، عَنْ عَطَاءٍ، عَنْ عَائِشَةَ ـ رضى الله عنها ـ قَالَتْ كَانَ النَّبِيُّ صلى الله عليه وسلم إِذَا رَأَى مَخِيلَةً فِي السَّمَاءِ أَقْبَلَ وَأَدْبَرَ وَدَخَلَ وَخَرَجَ وَتَغَيَّرَ وَجْهُهُ، فَإِذَا أَمْطَرَتِ السَّمَاءُ سُرِّيَ عَنْهُ، فَعَرَّفَتْهُ عَائِشَةُ ذَلِكَ، فَقَالَ النَّبِيُّ صلى الله عليه وسلم ‏"‏ مَا أَدْرِي لَعَلَّهُ كَمَا قَالَ قَوْمٌ ‏{‏فَلَمَّا رَأَوْهُ عَارِضًا مُسْتَقْبِلَ أَوْدِيَتِهِمْ‏}‏ ‏"‏‏.‏ الآيَةَ‏

Narrated By Ata : 'Aisha said If the Prophet saw a cloud In the sky, he would walk to and fro in agitation, go out and come in, and the colour of his face would change, and if it rained, he would feel relaxed." So 'Aisha knew that state of his. So the Prophet said, I don't know (am afraid), it may be similar to what happened to some people referred to in the Holy Qur'an in the following Verse: "Then when they saw it as a dense cloud coming towards their valleys, they said, 'This is a cloud bringing us rain!' Nay, but, it is that (torment) which you were asking to be hastened a wind wherein is severe torment." (46.24)