Your Lord knows that you stay up nearly two-thirds of the night, or half of it, or one-third of it, along with a group of those with you. God designed the night and the day. He knows that you are unable to sustain it, so He has pardoned you. So read of the Quran what is possible for you. He knows that some of you may be ill; and others travelling through the land, seeking God’s bounty; and others fighting in God’s cause. So read of it what is possible for you, and observe the prayers, and give regular charity, and lend God a generous loan. Whatever good you advance for yourselves, you will find it with God, better and generously rewarded. And seek God’s forgiveness, for God is Forgiving and Merciful.

The Holy Quran · Al-Muzzammil (The Enshrouded One) · 73:20