Musnad Ahmad 30:2220

'Affan narrated to us, 'Abd al-Rahman ibn Ibrahim narrated to us, al-'Ala' narrated to us, from his father, from Abu Hurayrah, who said: A man came to the Messenger of Allah, peace and blessings of Allah be upon him, and said: "O Messenger of Allah, I have relatives whom I join, but they cut me off; I am forbearing toward them, but they act ignorantly toward me; and I do good to them, but they do evil to me." The Messenger of Allah, peace and blessings of Allah be upon him, said: "If it is as you say, it is as if you are feeding them hot ashes, and there will continue to be a supporter from Allah for you against them as long as you remain upon that."