Musnad Ahmad 937:176

'Abd al-Samad narrated to us, my father narrated to us, Husayn—meaning al-Mu'allim—narrated to us, from Ibn Buraydah, Yahya ibn Ya'mar narrated to me, that Abu al-Aswad narrated to him, from Abu Dharr, that he heard the Messenger of Allah (ﷺ) saying: "There is no man who claims [to be the son of] someone other than his father, while he knows it, except that he has committed disbelief. And whoever claims what is not his, he is not of us, and let him take his seat in the Fire. And whoever calls a man a disbeliever, or says: 'Enemy of Allah,' and he is not like that, it will only return upon him."