Musnad Abu Ya'la al-Mawsili 110:125

Hadba narrated to us, Wahb narrated to us, from Yunus bin Ubayd, Ammar bin Abi Ammar informed us, he said: I heard Ibn Abbas saying: The Messenger of Allah, may Allah bless him and grant him peace, passed away while he was sixty-five years old. And al-Hasan used to say: The Messenger of Allah, may Allah bless him and grant him peace, passed away while he was sixty years old.