Sahih Muslim , Book 54, Hadith 93 (In-Book) ⓘ
Abu Huraira reported that Allah's Messenger said: Kisra (Khusrau king of Persia) would die and Qaisar (Ceasar King of Rome) would die; there would be no Qaisar after him, but, by the One in Whose Hand is my life, you would spend their treasures in the cause of Allah.
حَدَّثَنَا عَمْرٌو النَّاقِدُ، وَابْنُ أَبِي عُمَرَ، - وَاللَّفْظُ لاِبْنِ أَبِي عُمَرَ - قَالاَ حَدَّثَنَا سُفْيَانُ، عَنِ الزُّهْرِيِّ، عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " قَدْ مَاتَ كِسْرَى فَلاَ كِسْرَى بَعْدَهُ وَإِذَا هَلَكَ قَيْصَرُ فَلاَ قَيْصَرَ بَعْدَهُ وَالَّذِي نَفْسِي بِيَدِهِ لَتُنْفَقَنَّ كُنُوزُهُمَا فِي سَبِيلِ اللَّهِ " .
also referenced under: Hadith 2918 (Reference) & Book 41, Hadith 6973 (USC-MSA)