Musnad Ahmad 33:754

Ya'qub narrated to us, Ibn Akhi Ibn Shihab narrated to us, from his uncle, and Abu Salamah ibn 'Abd al-Rahman narrated to me, that Jabir ibn 'Abd Allah informed him, that the Messenger of Allah (peace and blessings of Allah be upon him) decreed: "Whoever grants a person a life-tenancy (*'umra*) for him and his descendants, it belongs to the one to whom it was granted. He has finalized it away from its owner who granted it, and it does not fall into the inheritances of Allah and His right."