Hadith: I am barrier in front of fire.
It was narrated by ibn Adi in “al-Kamil”, ibn Asakir in “Tarih madinatul dimashk”, that Ali ibn Abi Talib (may Allah be pleased with him) said: “I am barrier in front of fire”.
Shaykhana Albani (rahimuhullah) in “Silsila ad-daifa” (#4924) said it’s fabrication.
Chain of this hadith contain Mosa ibn Taref, Qays ibn ar-Rabea and Abayah Al-Asadi.
Ibn Taref was weak, as Daraqutni said (Mizanul itidal 4/208/#8884). Same opinion shared ibn Maeen (Jarh wa tadeel 8/148). Dhahabi in the bio of Abaya, said that ibn Taref and Abaya were extreme shias.
Qays also was weak. Ahmad said that he was yatashayu with a lot of errors. Daraqutni said he was weak. Nasai said: “Abandoned”. Dhahabi said that he was saduq with bad memory (Mizanul itidal 3/393/#6911).
And see this also: Did imam Ahmad authenticate this hadith?