Musnad Ahmad 938:73

'Abd al-Razzaq narrated to us, Ma'mar narrated to us, from 'Amr ibn Dinar, from Tawus, from Hajar al-Madari, from Zayd ibn Thabit, who said: The Messenger of Allah (peace and blessings of Allah be upon him) said: "The *'Umra* (gift of a house for life) belongs to the heir."