The Messenger of Allah ﷺ said, "When Khosrow perishes, there will be no Khosrow after him, and when Caesar perishes, there will be no Caesar after him. By the One in whose hand my soul is, their treasures will surely be spent in the path of Allah."
قال رسول الله ﷺ: إذا هلك كسري فلا كسري بعده، وإن هلك قيصر فلا قيصر بعده، والذي نفسي بيده لتنفقن كنوزهما في سبيل الله.
Bukhari narrated it in the Book of the Obligation of Khumus (3121) and Muslim in the Book of Tribulations (2919), both from the hadith of Jareer, from Abdul-Malik bin Umayr, from Jabir bin Samura, and he mentioned it. The wording given here is Bukhari's.