Musnad Ahmad 907:134

'Abdullah narrated to us, Muhammad ibn Abi Bakr narrated to me, Abu 'Awanah narrated to us, from 'Abd al-Malik ibn 'Umayr, from Jabir ibn Samurah, from the Prophet, peace and blessings of Allah be upon him, who said: "When Caesar perishes, there will be no Caesar after him, and when Chosroes perishes, there will be no Chosroes after him. By the One in Whose hand is my soul, you will surely spend their treasures in the way of Allah."