Musnad Abu Ya'la al-Mawsili 42:122

Abu Bakr narrated to us, Qabisah narrated to us, from Sufyan, from Zayd ibn Aslam, from Iyad, from Abu Sa’id, who said: We used to grant inheritance to him during the time of the Messenger of Allah, peace and blessings of Allah be upon him—meaning the grandfather.