Musannaf Ibn Abi Shayba 33:672

Abu Usama narrated to us, he said: Al-A'mash narrated to us, he said: 'Umarah narrated to us, from Abu Ma'mar, he said: We were sitting with 'Amr ibn Shurahbil, and he said: "Go with us to the person who most resembles Abdullah in guidance, conduct, and appearance." We did not know who he was until we set off to 'Alqamah.