Sahih Bukhari
Oaths and Vows
Volume: 008 / Book Number: 078 / Hadith Number: 625
Narrated Jabir bin Samura:
The Prophet said, "If Caesar is ruined, there will be no Caesar after him; and if Khosrau is ruined, there will be no Khosrau, after him; and, by Him in Whose Hand my soul is, surely you will spend their treasures in Allah's Cause."