Musnad Ahmad 28:44

Ibn Numayr narrated to us, Uthman ibn Hakim narrated to us, from Abu Umamah ibn Sahl ibn Hunayf, from Abdullah ibn Amr, who said: We were sitting with the Prophet, may Allah bless him and grant him peace, and Amr ibn al-Aas had gone to put on his clothes to join me. While we were with him, he said: "A cursed man will enter upon you." By Allah, I did not cease to be fearful, watching whoever entered and exited, until so-and-so entered, meaning al-Hakam.