Musnad Ahmad 30:874

Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, he said: I heard al-'Ala' ibn 'Abd al-Rahman narrating from his father, from Abu Hurayrah: That a man said: "O Messenger of Allah, I have relatives whom I join, but they cut me off; I treat them well, but they treat me badly; and I am forbearing toward them, but they are ignorant toward me." He said: "If you are as you say, then 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."