Musnad Ahmad 907:20

'Affan narrated to us, Abu 'Awanah narrated to us, from Simak, from Jabir ibn Samurah, who said: I heard the Messenger of Allah, peace and blessings of Allah be upon him, saying: "A group of the Muslims, or of the believers, shall surely conquer the treasure of the family of Chosroes, which is in the White Palace."