And We appointed with Musa a time of thirty nights and completed them with ten (more), so the appointed time of his Lord was complete forty nights, and Musa said to his brother Haroun: Take my place among my people, and act well and do not follow the way of the mischief-makers.

And during a part of the night, pray Tahajjud beyond what is incumbent on you; maybe your Lord will raise you to a position of great glory.

What! he who is obedient during hours of the night, prostrating himself and standing, takes care of the hereafter and hopes for the mercy of his Lord! Say: Are those who know and those who do not know alike? Only the men of understanding are mindful.

He said: O my Lord! surely I have called my people by night and by day!

Surely your Lord knows that you pass in prayer nearly two-thirds of the night, and (sometimes) half of it, and (sometimes) a third of it, and (also) a party of those with you; and Allah measures the night and the day. He knows that you are not able to do it, so He has turned to you (mercifully), therefore read what is easy of the Quran. He knows that there must be among you sick, and others who travel in the land seeking of the bounty of Allah, and others who fight in Allah's way, therefore read as much of it as is easy (to you), and keep up prayer and pay the poor-rate and offer to Allah a goodly gift, and whatever of good you send on beforehand for yourselves, you will find it with Allah; that is best and greatest in reward; and ask forgiveness of Allah; surely Allah is Forgiving, Merciful.