Time when IMAM MAHDI would come

Prophet Muhammad(saas) peace be upon him also told us the approximate time when IMAM MAHDI will come

Prophet Muhammed(saas) said,"My Ummah cant perish as I am at its beginning, Isa, son of Mariyum, at its end and the Mahdi from my progeny will be in the middle of it. But in between, there will be a large detracted group. Neither I belong to them nor do they belong to me."

The above tradition has been quoted from :
In Musnad of Imam Ahmad from Ibn AbbasRZ
By Abu Nu-aym Isphahani from Ibn AbbasRZ
In Kanzul Ummal from AliRZ
In Mishkat and its commentaries Mirqat and Lumu'at from Imam Jafar and Razeem
By Hakim from Abdullah Ibn UmarRZ
In Tafseer-e-Madarik with some variance in words.
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