Ammar came in to see Ali, who greeted him saying, "Welcome to the good and purified one. I heard the Messenger of Allah ﷺ say, 'Ammar has been filled with faith to the very marrow of his bones.'"
دخل عمار على علي، فقال: مرحبا بالطيب المطيب. سمعت رسول الله ﷺ يقول: ملئ عمار إيمانا إلى مشاشه.
Ibn Majah reported it (147), Nasr bin Ali Jahdami told us, he said, Utham bin Ali told us, from Amash, from Abu Ishaq, from Hani bin Hani, and he related the hadith. Ibn Hibban graded it sahih (7076), and he reported it through the route of Utham bin Ali, with the same chain, in similar wording. Hani bin Hani is the Hamdani, and no one narrated from him except Abu Ishaq. Ibn Hibban mentioned him in Thiqat (5/509), and Nasai said, "There is no harm in him," but Ibn Madini declared him unknown. Harmala reported from Shafii, "Hani bin Hani is not known, and the scholars of hadith attribute his narration to the uncertainty of his status."I say, but he has a corroborator, for Nasai reported it (5007) through another route, from Amr bin Shurahbil, from a man among the companions of the Prophet ﷺ, who said, the Messenger of Allah ﷺ said, and he related it similarly. Amr bin Shurahbil is the Hamdani, Abu Maysara al-Kufi, who narrated from Ali bin Abu Talib and other companions, and he is among the men of the Sahihayn. So perhaps the unnamed man in the chain is Ali bin Abu Talib, and even if it were someone else, it would not matter, because the anonymity of a companion does not harm the soundness of a hadith.Ibn Hajar mentioned this hadith in the biography of Ammar bin Yasir in Isabah, but he attributed it to Tirmidhi and Ibn Majah, and graded its chain hasan, though his attribution to Tirmidhi was a mistake on his part. As for his saying, "his bones," he means the tips of his bones, by which he intends the strength of his faith.