The One Covering Himself - 73:20
Your Lord knows that you and a group of your companions get up less than two-thirds, half and one-third of the night. Allah determines the amount of the night and the day. He has forgiven you because He knows that you cannot do it. So read from the Qur´an as much as is easy for you. He knows that among you are the sick, those who seek sustenance from the bounty of Allah in the earth, and those who fight in the way of Allah. Read from it as much as is easy for you. Observe the prayer, pay the zakat, and make a debt to Allah through good deeds. Whatever good you do for yourselves you will find a better and greater reward in the sight of Allah. Seek forgiveness from Allah; Allah is Forgiving, Merciful.
What is the purpose of prayer?
The Cow/2:45
Seek help by enduring hardship (patience) and prayer. Surely this is burdensome to the people, except for those who are reverent.
The Spider/29:45
Read from the Book which We have revealed to you and observe the prayer. For prayer discourages from abominable and evil things. The remembrance of Allah (through prayer) is most important. Allah knows what you do.
Prophet Hud/11:87
"They said: "Shu´ayb, does your prayer require us to give up what our ancestors used to serve or to turn our trade as we wish? You are indeed mild-tempered and wise."
Ta-Ha/20:14
I, yes, I am Allah; there is no god but Me. Serve Me and observe the prayer in remembrance of Me.
The Most High/87:15
He who remembers the name of his Lord and prays.
The Victory/48:29
Muhammad, the Messenger of Allah, and those who are with him are harsh against the disbelievers and merciful among themselves. You see them bowing down and prostrating themselves, asking Allah for His favor and pleasure. On their faces are the marks of prostration. This is their character in the Torah. And in the Gospel they are like a plant that has sprouted and grown strong and thickened and stood up on its stems, delighting the cultivators. He enrages the disbelievers with them. Allah has promised forgiveness and a great reward to those of them who believe and do righteous deeds.