Sahih Bukhari
Fighting for the Cause of Allah (Jihaad)
Volume: 004 / Book Number: 052 / Hadith Number: 267
Narrated Abu Huraira:
The Prophet said, "Khosrau will be ruined, and there will be no Khosrau after him, and Caesar will surely be ruined and there will be no Caesar after him, and you will spend their treasures in Allah's Cause." He called, "War is deceit'.