Musnad Ahmad 28:300

Ishaq ibn Yusuf narrated to us, Sufyan narrated to us, from al-Hasan ibn ‘Amr, from Ibn Muslim—[‘Abdullah ibn Ahmad said:] It was in my father’s book: "from al-Hasan ibn Muslim," so he struck through "al-Hasan" and said: "from Ibn Muslim," and it is only Muhammad ibn Muslim, Abu al-Zubayr. Al-Azraq erred [by saying] from ‘Abdullah ibn ‘Amr, from the Prophet, peace and blessings of Allah be upon him, who said: "When you see my nation not saying to the oppressor among them, 'You are an oppressor,' then farewell has been bid to them."