Musnad Ahmad 2:242

'Abdullah ibn Zayd narrated to us, Ibn Lahi'ah narrated to us, from 'Amr ibn Shu'ayb, from his father, from his grandfather, from 'Umar ibn al-Khattab, who said: I heard the Messenger of Allah (peace and blessings of Allah be upon him) saying: "The right of wala' (patronage) is inherited by whoever inherits the wealth, whether it be a father or a son."