Q- It is said at the battle of Khaybar, Sayyiduna Ali (radiyallahu ‘anhu) lifted a heavy door and used it a shield. After the battle it took forty Sahabah to pick it up. Is this Hadith authentic?
The incident in question has been recorded with a few chains. However ‘Allamah Sakhawi (rahimahullah) has declared all of these chains as very weak (kulluha wahiyah) and states that due to this, many ‘Ulama have rejected [the authenticity] of this incident.
‘Allamah Sakhawi (rahimahullah) has further pointed out a narrator in one of the chains who is a Shi’i, implying that the narration reported through him is unacceptable since it supports his corrupt beliefs. Imam Bayhaqi and Hafiz Ibn Kathir (rahimahumallah) have also pointed out the weakness of the other chains.
(Refer: Al Maqasidul Hasanah, Hadith: 418, Kashful Khafa, vol. 1 pg. 420 Hadith: 1168, Al Asrarul Marfu’ah, Hadith: 180. Also see Fathul Bari, under Hadith: 4210 and Footnotes of Musannaf Ibn Abi Shaybah of Shaykh Muhammad ‘Awwamah. Hadith: 32802)
And Allah Ta’ala Knows best