The Holy Prophet (SAW) has said:

"One who recites 10 aayat of the Quran every night, will not be counted among the heedless, negligent ones (Ghafileen); and one who recites 50 aayat will be written as those who remember Allah (Dhakireen); and one who recites 100 aayat (every night) will be written down as the obedient and worshippers  of Allah (Qaaniteen)."

Thawaab-ul-Amaal
page 232