Musnad Ahmad 1034:167

Waki’ narrated to us, from Isra’il, from Abu Ishaq, from ‘Abd al-Rahman ibn Yazid, who said: We said to Hudhayfah: "Inform us about the person who is closest in manner to the Messenger of Allah, may Allah bless him and grant him peace, so that we may take from him and listen to him." He said: "The person who was most similar in manner, conduct, and guidance to the Messenger of Allah, may Allah bless him and grant him peace, was Ibn Umm ‘Abd."