Fighting for the Cause of Allah (Jihaad)
Bukhari :: Book 4 :: Volume 52 :: Hadith 188
Narrated Abu Huraira:
Tufail bin 'Amr Ad-Dausi and his companions came to the Prophet and said, "O Allah's Apostle! The people of the tribe of Daus disobeyed and refused to follow you; so invoke Allah against them." The people said, "The tribe of Daus is ruined." The Prophet said, "O Allah! Give guidance to the people of Daus, and let them embrace Islam."