One who recites ten verses (ayat) of the Qur'an every night will not be counted amongst the negligent ones (Ghafilin); and one who recites fifty verses (ayat) will be written as those who remember Allah (Dhakirin); and one who recites one hundred verses (ayat) will be written down as the obedient and worshipper of Allah (Qanitin).

Thawabul A'mal, Page 232 - Shi'ite Hadith