prayer is incumbent over every (dead) Muslim, whether he be righteous or unrighteous, even though he be guilty of mortal sins."'—Abú Dáud.
On What is Necessary for the Leader of Prayers
It is related from Abú Hurairah that, 'The Apostle of God said, "When any one of you prays for the people (as leader), then let him be brief, because amongst them are sick and weak and aged persons; and when any one of you prays for himself, then let him be as long as he likes."'—Muslim, Al Bukhárí.
It is related from Qais binuʾl-abú Ḥázim that he said, 'Abú Masʿúd informed me that a man said, "O Apostle of God, by God! verily I delay to come to the morning prayers on account of so-and-so making the prayers so long for us." Then I never saw the Apostle of God more angry in the place of instruction than he was then. Afterwards the Prophet said, "Verily amongst you are those who cause people to withdraw themselves (from prayers); therefore whoever of you prays (as leader) for the people, let him be indulgent, because there are amongst them, weak and aged and indigent."'—Muslim, Al Bukhárí
On the Duties of a Congregation
It is related from Abú Hurairah that, 'The Apostle of God said, "Do not hasten before the leader of the prayers (in reciting). When he says, 'God is great', then do ye say 'God is great', and when he says, 'Nor of those who go astray,' then do ye say, 'Amen,' and when he bows down, then do ye bow down, and when he repeats the words, 'God hears him who praises Him,' then say ye, 'O God our Lord, to Thee be the praise.'"'—Muslim, Al Bukhárí; except, that Al Bukhárí does not mention the words 'When he says, "Nor of those who go astray."'
It is related from ʿÁyesha that she said, 'When the Prophet became oppressed (with the sickness from which he died), Bilál came to call him to prayers, and he said, "Command Abú Bakr to pray for the people (as leader)." So Abú Bakr prayed those days. Afterwards the Prophet felt some alleviation (of his sickness) and rose up and was led between two men, and his feet dragged upon the earth, until he entered the mosque.
