Dear Doctor Sir,
Please explain the following lines of SURAT 73:20
He has known that you [Muslims] will not be able to do it and has turned to you in forgiveness, so recite what is easy [for you] of the Qur'an.
The line in this verse goes like this: 73.20 Allah measures the night and the day. He knows that ye count it not, and turns unto you in mercy.
Any verse in Quran does not refer to 'Muslims' but to mankind; Allah has created Night and Day for the mankind to enlighten and reassure them by the Night; and enliven and prosper by the Day. The Night is created for us to rest therein and to seek forgiveness for all that we had done during the Day against our conscience, The Book. We are accountable for what we had committed during our Day time and it is time to seek from His Mercy. The Night proceeds with the purification of our conscience, The Book, until the Night has cleansed us of our addiction to evil. So for each and every one of us there is a period of awakening in our conscience before the sleep overtakes us. Early to bed as the Night falls thus gives mankind chance for this retreat in order that they are pruned and primed by the Nights. You cannot fall asleep without this retreat for a wonderful short sleep. Your night is over when Allah says: 'wakeup, enough of it!' When you are awakened thus the time may be deep into the Night or early hours; never go back to sleep without remembering Allah dutifully and with gratitude; if you are sure it is Allah who gives you sleep, then it is He who wakes you up. If we honour Allah then it is that we wake up and bring to our memory and praise His Glory for all the good He has bestowed upon us during the Day and during the Night.
In this way Allah says some of you stand steadfast in My remembrance during the times of wakefulness, in gratitude - Night or Day, except for the naps now and then as per My allowance to you. Therefore you are not the ones who calculate the Night and the Day. And until this day Allah had forgiven you for this and has turned to you in Mercy.