Making Up the Missed Prayers
     The scholars agree that it is obligatory for one who has    forgotten the salah or slept through its time to make up    the missed [qada') prayer. This opinion is based on the    hadith of the Prophet mentioned earlier: "There is no    negligence while one is asleep but forgetfulness occurs    when one is awake. If one of you forgets the prayer or    sleeps through its time, then he should perform the salah    when he recalls it." If one falls unconscious, then he    need not repeat the salah, unless he regains his    consciousness with enough time to purify himself and    perform the salah within its proper time.
         'Abdurrazaq relates from Naf'i that Ibn 'Umar once fell    sick and became unconscious and missed the prayer. When    he regained his consciousness, he did not make up the    missed prayer.
         Ibn Juraij reports from Ibn Tawus on the authority of his    father that if a sick person becomes unconscious, he is    not to make up the prayers he missed .
         Mu'ammar relates: "I asked az-Zuhri about one who becomes    unconscious, and he said that he is not to make up the    salah he missed."
         Hamad ibn Salamah relates from Yunus ibn 'Ubaid that both    al-Hassan al-Basri and Muhammad ibn Sireen said that a    person who falls unconscious is not to make up the    prayers he may miss.
         Concerning missing a salah intentionally, the majority of    the scholars say that it is a sin and the missed salah    must be made up for. Ibn Taimaiyyah says:    
In law, there is no way for one who leaves a salah intentionally to make it up
     He may however, resort to increasing his voluntary and    supererogatory acts. Ibn Hazm has thoroughly discussed    this question. The following is a summary of what he says    on this subject:         Concerning one who leaves a salah intentionally until its    time expires, he will never be able to make up for that    salah. Such a person should turn to Allah and ask His    forgivness and increase his good deeds and nawafil in    order to increase his weight [of good] on the Day of    Resurrection. Abu Hanifah, Malik, and ash-Shaf'i say that    he can make up the prayer after its time has expired, and    Malik and Abu Hanifa even say that if a person    intentionally misses a prayer or a few prayers, then he    is to make up those prayers before he prays the present    salah, even if he has missed all five prayers and should,    while making them up, miss the present salah. They say    that if he missed more than five prayers, he is to begin    by praying the salah whose time is present [and then he    is to make up the prayers he missed]. The proof for our    position [i.e, the position of Ibn Hazm] is found in the    words of Allah, the Exalted: "Woe unto the worshippers    who are heedless of their prayers,'' and: "And then there    succeeded them a later generation who wasted the prayers    and followed their own lusts, but they will meet with    destruction." If one who intentionally misses a salah    could make it up later, then why is it mentioned with    affliction or transgression? Of course, there is no    affliction or transgression on one who delays the salah.
    But the case of one who procrastinates until the last    portion of its permissible time expires is quite    different. Allah, the Exalted, has appointed certain    times for the fard salah; both the beginning time and the    ending time for the salah have been established, and    there is no difference between praying a salah before its    time and praying it after its proper time elapses    because, in both cases the salah is not performed within    its prescribed time. This is not to draw an analogy    between one and the other but it is applying the same    rule to them as they both must be performed within the    limits set by Allah. Allah, the Exalted, says: "Whoever    transgresses the limits set by Allah has verily wronged    his own soul!"     
In law, there is no way for one who leaves a salah intentionally to make it up
     Ibn Hazm discusses this point at great length, and adds:    "If making up a salah is obligatory for one who has left    a salah, even after its time has expired, why is it that    Allah and His Messenger have chosen not to mention that    fact as (surely) they did not forget it: "And your Lord    is not forgetful!" Any law that is not based on the    Qur'an or the sunnah is not valid. It has been    authentically reported that the Prophet said: "Whoever    misses the 'asr salah, it is as if he has lost his family    and his property." It is correct to say that if one    "misses" something, he cannot make it up, for if he makes    it up or could make it up, the act would not be "missed."
    The entire Muslim ummah is in agreement with the    statement and ruling that if the time of the salah has    elapsed, then the salah is "over" [i.e., "qada" in    Arabic], but if one can make it up, the statement that    the salah is "over" becomes false and untrue; therefore,    there is no way that it could ever be made up. The people    who agree with us on this include 'Umar ibn al-Khattab,    his son 'Abdullah, Sa'd ibn Abi Waqas, Salman al-Farsi,    ibn Mas'ud, al-Qasim ibn Muhammad ibn Abu Bakr, Budail    al-'Uqaili, Muhammad ibn Sireen, Mutraf ibn 'Abdullah,    'Umar ibn 'Abdulaziz, and others. Allah has left no    excuse, for anyone required to perform the salah, to    delay the salah from its proper time for any reason    whatsoever, not even during times of fighting, fear,    extreme illness, or travelling. Allah says: "And when you    are among them and arrange them for salah, let only one    party be with you" And: "But if you are in danger, then    walking or riding." Allah, the Exalted, does not permit    even the extremely sick person to delay the salah. In    fact, such a person has been ordered to pray sitting, if    he cannot pray standing, and if he cannot pray sitting,    then he may pray on his side. Also, if one cannot make    ablution with water, he may make tayammum; and if he    cannot find soil to make tayammum, he may still pray.
    Whence has the permission been obtained that one may    intentionally leave the salah until its time is finished    and who has ordered that it be performed after its time    and how is it that the belated salah would be sufficient?    None of this is derived from the Qur'an, Sunnah, Qiyas    (analogical reasoning), and so forth.
         Ibn Hazm further says: "Concerning our statement that the    one who intentionally leaves a salah until its time    expires is to repent to Allah, the Exalted, ask for His    forgiveness, pray an increased number of nawafil, and do    good deeds. This statement is based on Allah's words:    "Then there succeeded them a generation who missed    prayers and followed after lusts. But they will meet    destruction save him who repents and believes and does    right. Such will enter the garden and will not be    wronged," and: "...those who, when they do an evil thing    or wrong themselves, remember Allah and implore    forgiveness for their sins - who forgives sins, save    Allah - and will not knowingly repeat the wrong they    did," and: "Whoever does an atom's weight of good shall    see it and whoever does an atom's weight of evil shall    see it," and: "...We set a just balance for the day of    resurrection so no soul shall be wronged."
         This [Muslim] ummah is in agreement, and there are texts    that state that voluntary acts are a type of good deeds    and Allah knows how much they are really worth. It    necessarily follows that a number of voluntary works may    be equivalent in merit to an obligatory deed and may even    amount to a greater merit. Furthermore, Allah has    informed us that He does not waste the action of any    person and that the good deeds erase the evil ones.
    
We are identifying and building the related set of Ayahs for this Hadith. Please share your feedback and let us know if you identify any referencing issues.
"When a person dies, his works end, except for three: ongoing charity, knowledge that is benefited from, and a righteous child who prays for him."
Prophet Mohammed (PBUH)
"The best of what a man leaves behind are three: a righteous child who supplicates for him, ongoing charity the reward of which reaches him, and knowledge that is acted upon after him."
Sunan Ibn Mājah
"Every day two angels come down from Heaven and one of them says, 'O Allah! Compensate every person who spends in Your Cause,' and the other (angel) says, 'O Allah! Destroy every miser.'"
Sahih Bukhari