Musnad Ahmad 907:206

Hassan ibn Musa narrated to us, Shaiban narrated to us, from Abd al-Malik, from Jabir ibn Samurah, who said: I heard the Messenger of Allah, peace and blessings of Allah be upon him, saying: "When Caesar is gone, there will be no Caesar after him, and when Chosroes is gone, there will be no Chosroes after him. By the One in Whose hand is the soul of Muhammad, you will surely spend their treasures in the way of Allah."