Musnad Ahmad 9:21

Mu'awiyah ibn 'Amr narrated to us, Za'idah narrated to us, Husayn ibn 'Abd al-Rahman narrated to us, from Hilal ibn Yasaf, from 'Abd Allah ibn Zalim al-Tamimi, from Sa'id ibn Zayd ibn 'Amr ibn Nufayl, who said: I bear witness that 'Ali is among the people of Paradise. I said: "And what is that?" He said: "He is among the nine, and if I wished to name the tenth, I would name him." He said: Hira' shook, so the Messenger of Allah (peace and blessings of Allah be upon him) said: "Be still, Hira', for there is upon you none but a Prophet, or a Siddiq (truthful one), or a martyr." He said: "The Messenger of Allah (peace and blessings of Allah be upon him), Abu Bakr, 'Umar, 'Ali, 'Uthman, Talhah, al-Zubayr, 'Abd al-Rahman ibn 'Awf, and Sa'd," and I—meaning Sa'id himself.