Musnad Ahmad 5:119

Hashim and Hassan narrated to us, they said: Shayban narrated to us, from Asim, from Zirr ibn Hubaysh, who said: Ibn Jurmuz sought permission to enter upon Ali. He said: "Who is this?" They said: "Ibn Jurmuz is seeking permission." He said: "Give him permission. Let the killer of al-Zubayr enter the Fire. I heard the Messenger of Allah, peace and blessings of Allah be upon him, say: 'Indeed, every prophet has a disciple (hawari), and my disciple is al-Zubayr.'"