Sahih Bukhari Volume 4, Book 54, Hadith Number 428.

Narated 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 color 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 Quran 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)