Grading: Its chain is "very weak" (da'if jiddan).
Technical note / Defect ('illah): The reason for this is "Amr bin Abd al-Ghaffar" (al-Fuqaymi); he is "matruk al-hadith" (abandoned in hadith), and some accused him of lying. He erred in the chain of this hadith. For "Qutbah bin Abd al-Aziz" (who is thiqah and the owner of a written record) contradicted him and narrated it from al-A'mash (Sulayman bin Mihran), from Adi bin Thabit, from Salim bin Abi al-Ja'd "mursal". In the route of al-A'mash from Adi bin Thabit, this "mursal" narration is the correct one, even though the report (its text) is sahih through another route, as will be explained later.

Reference / Source: Al-Ajurri narrated it in "al-Shari'ah" (1718), Ibn Adi in "al-Kamil" (5/ 147) and Abu Tahir al-Mukhallis in "al-Mukhallisiyyat" (1645), by two routes from Amr bin Abd al-Ghaffar, with this same chain.

Reference / Source: Ibn Abi Shaybah (12/ 104 and 14/ 518) narrated it through Yahya bin Adam, from Qutbah bin Abd al-Aziz, from al-A'mash, from Adi bin Thabit, from Salim bin Abi al-Ja'd "mursal".
Grading: All of its narrators, to the last of them, are "thiqah"; this is why al-Mundhiri said in "al-Targhib" (2/ 206): "It is mursal with a good (jayyid) chain."

Corroborating chains and supporting reports: In this chapter there is a "marfu'" narration from Abu Hurayrah (may Allah be pleased with him) that will come in the author's (al-Hakim's) collection at number (5008); its narrators are thiqah, but there is disagreement over whether it is "connected" or "munqati'", which will be explained there.

Corroborating chains and supporting reports: And a "marfu'" narration from Ibn Abbas (may Allah be pleased with him) will come in the author's collection at numbers (4951 and 4997) through various routes. Al-Mundhiri in "al-Targhib" (2/ 206) and al-Hafiz Ibn Hajar in "al-Fath" (11/ 149) declared some of those routes "strong".

Corroborating chains and supporting reports: The "marfu'" narration of Isma'il bin Abi Khalid from a man is in Ibn Sa'd's "al-Tabaqat" (4/ 35); its narrators are thiqah. If that unnamed man is a "Companion", then the chain is sahih, for Isma'il narrated from some Companions who died late.

Corroborating chains and supporting reports: And the "mursal" narration of Musa bin Uqbah is in al-Bayhaqi's "Dala'il al-Nubuwwah" (4/ 364-365) and Ibn Asakir's "Tarikh Dimashq" (2/ 10); there is no harm in its narrators.

Corroborating chains and supporting reports: The hadith of Abd Allah bin Umar (may Allah be pleased with him) is in al-Bukhari (3709, 4264) and al-Nasa'i (8102): "Whenever he greeted Abd Allah bin Ja'far (may Allah be pleased with him), he would say: 'Al-salamu alayka, ya Ibn Dhi al-Janahayn' (Peace be upon you, O son of the one with the two wings)." This narration will come in the author's collection at number (4400).

Technical note / Defect ('illah): All of these narrations revolve around "Amr bin Abd al-Ghaffar", and he is "matruk", as has passed.
Grading: This is why al-Dhahabi said in his "Talkhis": "All of these narrations from al-Bara' (bin Azib) are weak."