Musnad Abu Ya'la al-Mawsili 155:128

Mansur ibn Abi Muzahim narrated to us, Abu Uways narrated to us, from al-Zuhri, that Sa'id ibn al-Musayyib and Abu Salamah ibn 'Abd al-Rahman narrated to him, that Abu Hurayrah narrated to them: That the Messenger of Allah (may Allah bless him and grant him peace) announced to them the death of al-Najashi on the day he died. He said: "Seek forgiveness for your brother."