Musnad Abu Ya'la al-Mawsili 3:144

Al-Muqaddami and al-Hasan ibn Hammad narrated to us, they said: 'Atham ibn 'Ali narrated to us, al-A'mash narrated to us, from Abu Ishaq, from Hani' ibn Hani', who said: We were sitting with 'Ali when 'Ammar entered. He said: "Welcome to the pure, the purified. I heard the Messenger of Allah, may Allah bless him and grant him peace, say: 'Ammar is filled with faith up to his marrow.'"