O you who wraps himself [in clothing], stand [to pray] at night, except for a little. Half of it, or subtract from it a little. Or add to it, and recite the Qur’ān with measured rhytmic recitation. Indeed, We will cast upon you a weighty word (revelation). Indeed, the rising (to pray) at night is difficult and most potent for understanding (of the Quran) and more suitable for reciting (the Quran). Indeed, for you in the day is prolonged occupation.