Musnad Ahmad 943:0

Al-Ash'ath ibn Qays al-Kindi said: I came to the Messenger of Allah (ﷺ) with a delegation from Kindah. They said: "O Messenger of Allah, we are your cousins." He (ﷺ) smiled and said: "There is no lineage after Ma'add, but we are the sons of al-Nadr ibn Kinanah." He then said: "Do not attribute yourselves to other than your fathers, for it is disbelief (kufr) to disown your father, even if it is only a span. Whoever disowns his father, or claims a lineage that is not his, then upon him is the curse of Allah, the angels, and all the people. Allah will not accept from him on the Day of Resurrection any obligatory or supererogatory deed."