Messenger of Allah ﷺ said, "If Khosrau is ruined, there will be no Khosrau after him; and if Caesar is ruined, there will be no Caesar after him. By Him in Whose Hand Muhammad's soul is, surely you will spend their treasures in Allah's Cause."
قَالَ رَسُولُ اللَّهِ ﷺ إِذَا هَلَكَ كِسْرَى فَلاَ كِسْرَى بَعْدَهُ وَإِذَا هَلَكَ قَيْصَرُ فَلاَ قَيْصَرَ بَعْدَهُ وَالَّذِي نَفْسُ مُحَمَّدٍ بِيَدِهِ لَتُنْفَقَنَّ كُنُوزُهُمَا فِي سَبِيلِ اللَّهِ