Musnad Ahmad 5:294

Aswad, meaning Ibn ‘Amir, narrated to us, Isra’il informed us, from Abu Ishaq, from Hani’ ibn Hani’, from ‘Ali, who said: I came to the Prophet, may Allah bless him and grant him peace, along with Ja‘far and Zayd. He said: He said to Zayd, "You are my freedman (mawla)," so he hopped. He said: And he said to Ja‘far, "You resemble my physical appearance and my character," so he hopped behind Zayd. He said: And he said to me, "You are from me, and I am from you," so I hopped behind Ja‘far.