Musannaf Ibn Abi Shayba 27:617

'Atham ibn 'Ali narrated to us, he said: Al-A'mash narrated to us, from Abu Ishaq, from Hani' ibn Hani', he said: 'Ammar sought permission [to enter] upon 'Ali. He said: "Welcome to the good, the made good. I heard the Messenger of Allah, peace and blessings of Allah be upon him, say: 'Ammar is filled with faith up to his bones.'"