Musnad Abu Ya'la al-Mawsili 156:1

Ishaq ibn Abi Isra'il narrated to us, Hajjaj ibn Muhammad narrated to us, from Hisham ibn Ziyad, from al-Hasan, he said: I heard Abu Hurayrah saying: The Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever recites Ya-Sin in a night, he wakes up forgiven. And whoever recites Ha-Mim in which al-Dukhan (the Smoke) is mentioned on the night of Jumu'ah, he wakes up forgiven."