Musnad Ahmad 9:14

Muhammad ibn Ja‘far narrated to us, Shu‘bah narrated to us, from Husayn, from Hilal ibn Yasaf, from ‘Abdullah ibn Zalim, who said: Al-Mughirah ibn Shu‘bah delivered a sermon and disparaged ‘Ali. Sa‘id ibn Zayd went out and said: "Do you not wonder at this man who insults ‘Ali? I bear witness regarding the Messenger of Allah (may Allah bless him and grant him peace) that we were upon Hira’—or Uhud—and the Messenger of Allah (may Allah bless him and grant him peace) said: 'Be firm, Hira’—or Uhud—for there is upon you none but a truthful one (Siddiq) or a martyr.'" The Prophet (may Allah bless him and grant him peace) named the ten, and he named: Abu Bakr, ‘Umar, ‘Uthman, ‘Ali, Talhah, al-Zubayr, Sa‘d, and ‘Abd al-Rahman ibn ‘Awf, and he named himself, Sa‘id.