Musannaf Ibn Abi Shayba 13:2659

Abu Bakr narrated to us, he said: Waki’ narrated to us, he said: Sufyan narrated to us, from Abu al-Zubayr, from Jabir, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Retain your wealth for yourselves and do not grant it as *‘umra* (life-tenure). For whoever is granted an *‘umra*, it belongs to the one who inherits it."