Sahih Bukhari Volume 004, Book 052, Hadith Number 090.
Hadith Section/Book: Sahih Bukhari Sahih Bukhari Book 52. Fighting for the Cause of Allah (Jihaad)
Narated By Al-Bara : On the day (of the battle) of Al-Ahzab (i.e. clans) I saw the Prophet carrying earth, and the earth was covering the whiteness of his abdomen. And he was saying, "Without You (O Allah!) we would have got no guidance, nor given in charity, nor prayed. So please bless us with tranquility and make firm our feet when we meet our enemies. Indeed (these) people have rebelled against (oppressed) us but never shall we yield if they try to bring affliction upon us."