The Messenger of Allah ﷺ said, "Ammar is filled with faith to the very marrow of his bones."
قال رسول الله ﷺ: ملئ عمار إيمانا إلى مشاشه.
Reported by Nasai (5007), and Hakim graded it sahih (3/392–393), both through routes from Abdul-Rahman (that is, Ibn Mahdi), from Sufyan (that is, Thawri), from Amash, from Abu Ammar (whose name is Urayb bin Humayd Hamdani), from Amr bin Shurahbil, from a man among the companions of the Prophet ﷺ, who related it. Its chain is sahih. Ibn Hajar also graded it sahih in Fath al-Bari (7/92).It was also reported by Ibn Abu Shayba (30986) and Ahmad in Fadail (1600), both from Waki, from Sufyan, from Amash, with this same chain, but as a mursal report. This does not harm the hadith, since both Abdul-Rahman bin Mahdi and Waki are among the most reliable transmitters of Thawri's material, so perhaps Thawri narrated this hadith both ways.A report with the same meaning has been narrated from Ayesha, who said, "There was no companion of the Messenger of Allah ﷺ about whom, had I wished, I could have said something, except for Ammar, for I heard the Messenger of Allah ﷺ say, 'He has been filled with faith up to his very bones.'"This was reported by Bazzar in Kashf Astar (2685) from Muhammad bin Yazid Abu Hisham, who said, Yahya bin Yaman told us, Sufyan (that is, Thawri) told us, from Salama bin Kuhayl, from Dharr (that is, Ibn Abdullah), from Saeed bin Abdul-Rahman bin Abza, from his father, from Ayesha, who related it.Muhammad bin Yazid Abu Hisham Rafai is daif by the agreement of the scholars. Abu Hatim, Nasai, and Hakim Abu Ahmad all declared him daif. Ibn Hajar said in Taqrib, "He is not strong." Ibn Adi listed him among the teachers of Bukhari, and Khatib affirmed that Bukhari narrated from him, but Bukhari himself said, "I have seen them unanimous in judging him daif." End of quote. Despite this, Ibn Hajar graded his chain sahih in Fath al-Bari (7/92).