Musnad Ahmad 848:2

Isma'il narrated to us, Ayyub narrated to us, from Humayd ibn Hilal, from a man—Ayyub said: I think it is Khalid ibn Umayr—who said: I heard Utbah ibn Ghazwan delivering a sermon, and he mentioned the hadith. He said: "I have seen myself as the seventh of seven with the Messenger of Allah (may Allah bless him and grant him peace), or he said: among the companions of the Messenger of Allah (may Allah bless him and grant him peace), and we had no food except the trees, or he said: the leaves of the trees, until the corners of our mouths became ulcerated." My father said: "This Abu Na'amah is Amr ibn Isa, and Abu Na'amah al-Sa'di is another, older than this one, and this one is greater than that one."