The saying of the Prophet (peace and blessings be upon him) about the killer of Ammar (may Allah be pleased with him) and the one who takes his belongings

It is narrated from Sayyiduna Abdullah bin Amr (may Allah be pleased with them both) that two men came to Amr bin al-As quarrelling over the blood of Sayyiduna Ammar bin Yasir (may Allah be pleased with him) and his belongings. Amr said: Leave it, for I heard the Messenger of Allah (peace and blessings be upon him) say: "O Allah, Quraysh have become set against Ammar. The killer of Ammar and the one who strips him of his belongings are in the Fire."
Abd al-Rahman bin al-Mubarak, who is trustworthy (thiqah) and reliable, is alone in narrating this from Mu'tamir from his father. So if it is preserved (mahfuz), it is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim); and people generally narrated it from Mu'tamir, from Layth, from Mujahid.

It is narrated from Sayyiduna Ali (may Allah be pleased with him) that Sayyiduna Ammar bin Yasir (may Allah be pleased with him) sought permission from the Prophet (peace and blessings be upon him) to enter while I was with him (peace and blessings be upon him). He (peace and blessings be upon him) said: "Give him permission." Then when he entered, the Messenger of Allah (peace and blessings be upon him) said: "Welcome, O pure one who has been purified!"
The chain of this hadith is sahih (authentic), but the two Shaykhs did not record it.

It is narrated from Harithah bin Mudarrib that Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) wrote to us: "I am sending to you Ammar bin Yasir as governor, and Abdullah bin Mas'ud as teacher and minister. These two are among the distinguished Companions of Muhammad (peace and blessings be upon him) and among the people of Badr, so listen to them. I have appointed Ibn Mas'ud over your treasury (Bayt al-Mal), so listen to them, learn from them and follow them. And indeed I have preferred you over myself in the matter of Abdullah (bin Mas'ud) (by sending him to you instead of keeping him with me)."
This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), and they did not record it.