Musnad Ahmad 435:56

'Affan narrated to us, Hammad bin Salamah narrated to us, he said: 'Abdullah bin Muhammad bin 'Aqil informed us, from Muhammad bin 'Ali ibn al-Hanafiyyah, from Mu'awiyah bin Abi Sufyan, he said: I heard the Messenger of Allah, peace and blessings of Allah be upon him, saying: "The 'Umra (gift of a house for life) is permissible for those to whom it is given."