Musannaf Ibn Abi Shayba 13:2661

Abu Bakr narrated to us, he said: Waki’ narrated to us, he said: Sufyan narrated to us, from Ibn Abi Najih, 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 (life-gift) is an inheritance."