“Whoever recites Ya Sin in the night, will wake up forgiven, and whoever recites Ha Mim in which Ad-Dukhan (the Smoke) is mentioned, will wake up forgiven.) Its chain of narration is good (Jayyid). Ibn Hibban recorded in his Sahih that Jundub bin `Abdullah, may Allah be pleased with him, said, “The Messenger of Allah said:(Whoever recites Ya Sin in the night, seeking the Face of Allah, will be forgiven.)
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This is not authentic.