Abu Hurairah reported,
The Prophet ﷺ said, "There will be no Khosrau after Khosrau, and no Caesar after Caesar. By the One in whose hand is the soul of Muhammad, their treasures will surely be spent in the cause of Allah 
."
Ahmad 9636
Sahihحدثنا يحيى عن إسماعيل يعني ابن أبي خالد قال حدثنا زياد
عن أبي هريرة
عن النبي ﷺ قال لا كسرى بعد كسرى ولا قيصر بعد قيصر والذي نفس محمد بيده لتنفقن كنوزهما في سبيل الله عز وجل
Its isnad is sahih. Bukhari related it, 4/104, in the chapter on the fifth share, on the Prophet's statement that spoils of war were made lawful for you. Muslim related it, 4/237, no. 2918, in the chapter on tribulations, on the Hour not coming until a man passes by another man's grave. Tirmidhi related it, 4/497, no. 2216, in the chapter on tribulations, on what has been reported about when Khosrow perishes, and he said it is hasan sahih. And Tayalisi, no. 2452, in Al-Minhah.