Qiyam Al-Layl
Many Qur’aanic verses speak about the excellence of Qiyam and the merits of those people, who perform Qiyaam al-Layl on a regular basis.
For example, Allah describes the believers who deserve Jannah saying:
They (the believers) forsake their beds, to invoke their Lord in fear and hope; and they spend out of what We have bestowed on them.
[Soorah as-Sajdah (32): 16]
They (the pious) used to sleep but little at night.
[Soorah ath-Thariyat (51): 17]
Also, numerous Ahadeeth add to this subject, narrated Abu Hurayrah (radhi allahu anhu):
The Messenger of Allah (sallallahu alaihi wa-sallam) said:
The best prayer after those prescribed is (the prayer performed) in the depth of night.”
[Saheeh Muslim and Musnad Ahmad]
He (sallallahu alaihi wa-sallam) also said:
The most beloved prayer to Allah was of Dawud (alaihi as-salaam). He slept one half of the night, got up (and prayed) for one third, and then slept (the remaining) one sixth.
[Saheeh al-Bukharee and Saheeh Muslim]