Sahih al-Bukhari, Hadith 3618 ⓘ
Narrated Abu Huraira: Allah's Messenger said, "When Khosrau perishes, there will be no (more) Khosrau after him, and when Caesar perishes, there will be no more Caesar after him. By Him in Whose Hands Muhammad's life is, you will spend the treasures of both of them in Allah's Cause."
حَدَّثَنَا يَحْيَى بْنُ بُكَيْرٍ، حَدَّثَنَا اللَّيْثُ، عَنْ يُونُسَ، عَنِ ابْنِ شِهَابٍ، قَالَ وَأَخْبَرَنِي ابْنُ الْمُسَيَّبِ، عَنْ أَبِي هُرَيْرَةَ، أَنَّهُ قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِذَا هَلَكَ كِسْرَى فَلاَ كِسْرَى بَعْدَهُ، وَإِذَا هَلَكَ قَيْصَرُ فَلاَ قَيْصَرَ بَعْدَهُ، وَالَّذِي نَفْسُ مُحَمَّدٍ بِيَدِهِ لَتُنْفِقُنَّ كُنُوزَهُمَا فِي سَبِيلِ اللَّهِ " .
also referenced under: Book 61, Hadith 125 (In-Book) & Volume 4, Book 56, Hadith 815 (USC-MSA)