Musnad Ahmad 938:70

'Abd al-Razzaq narrated to us, Sufyan informed us, from Ibn Abi Najih, from Tawus, from a man, from Zayd ibn Thabit: "That the Messenger of Allah (peace and blessings of Allah be upon him) assigned the *ruqba* (conditional gift) to the one to whom it was granted, and the *umra* (life-interest gift) to the one to whom it was granted."