Allah, the Exalted, says:

"Guard strictly (the five obligatory) As-Salawat (the prayers) especially the middle Salat (i.e., the best prayer - `Asr).'' (2:238)

"But if they repent and perform As-Salat (Iqamat-as-Salat) and give Zakat, then leave their way free.'' (9:5)

Ibn Mas`ud (radiallahu anh) reported: I asked the Messenger of Allah (salallahu alayhi wasalam): "Which act is the best?'' He (SAW) said, "As-Salat at their fixed times.'' I asked, "What next?'' He (SAW) said, "Being dutiful to parents.'' I asked, "What next?'' He (SAW) said, "Striving (Jihad) in the way of Allah.''
[Al-Bukhari and Muslim].

Commentary: Every Salah should be performed at its proper time. Deliberate delay in performing is wrong. The ultimate result of deliberate delay is that one becomes sluggish and begins to ignore and neglect it by force of habit, which is obviously very dangerous. Imam Ash-Shafi`i (ra) is of the opinion that if a person shows such laziness in offering Salat that he misses its proper time, then he is liable to make penitence for it. If he does not do so, he should be killed.

Ibn `Umar (radiallahu anhuma) reported: The Messenger of Allah (salallahu alayhi wasalam) said, "Islam is based on five (pillars): testifying that there is no true god except Allah and that Muhammad (PBUH) is His slave and Messenger; performing of Salat (Iqamat-as-Salat); the payment of Zakat; performing Hajj (pilgrimage) to the House [of Allah (Ka`bah)]; and Saum (fasting) during the month of Ramadan.''
[Al-Bukhari and Muslim].

Commentary: In this Hadith, Islam has been compared to a building which rests on five pillars. As a building cannot stand without its foundation, similarly, Islam cannot exist without these pillars. For this reason, he who denies any one of these obligations is a disbeliever, and he who neglects any of them due to slackness or want of attention is a sinful and impious Muslim.

Ibn `Umar (radiallahu anhuma) reported: The Messenger of Allah (salallahu alayhi wasalam) said, "I have been commanded to fight against the people till they testify La ilaha illAllah (There is no true god except Allah) and that Muhammad (PBUH) is His slave and Messenger, and to establish As-Salat (Iqamat-as-Salat), and to pay Zakat; and if they do this, then their blood and property are secured except by the rights of Islam, and their accountability is left to Allah.''
[Al-Bukhari and Muslim].

Commentary: Here the word "An-Nas'' translated `the people' in the Hadith stands for those who associate others with Allah in worship. The people of the Book are not included among them. "Haqqul-Islam'' translated here as "the rights of Islam'' denotes legal castigation, etc. That is, the punishments which are given for crimes like fornication, murder, etc.

"Their accountability is left to Allah" means what is hidden in their hearts is left to Allah or the crimes which go undetected by the authorities concerned are in the Purview of Allah, Who will decide their case in the Hereafter.

Mu`adh (radiallahu anh) reported: The Messenger of Allah (salallahu alayhi wasalam) sent me as a governor to Yemen and (at the time of departure) he instructed me thus: "You will go to people of the Scripture (i.e., the Jews and the Christians). First of all invite them to testify that La ilaha ill Allah (There is no true god except Allah) and that Muhammad (PBUH) is His slave and Messenger; and if they accept this, then tell them that Allah has enjoined upon them five Salat (prayers) during the day and night; and if they accept it, then tell them that Allah has made the payment of Zakat obligatory upon them. It should be collected from their rich and distributed among their poor; and if they agree to it, don't take (as a share of Zakat) the best of their properties. Beware of the supplications of the oppressed, for there is no barrier between it and Allah.''
[Al-Bukhari and Muslim].

Jabir (radiallahu anh) reported: The Messenger of Allah (salallahu alayhi wa salam) said, "Between a man and kufr (disbelief and paganism) is the abandonment of Salat (prayer).''
[Muslim].

Buraidah (radiallahu anh) reported: Messenger of Allah (salallahu alayhi wa salam) said, "That which differentiates us from the kuffar (disbelievers) and the hypocrites is our performance of Salat. He who abandons it, becomes a kafir (disbeliever).''
[At-Tirmidhi].

Commentary: He who will be having the quality of Islam and will be particular in performing Salat regularly, will raise a wall between himself and Kufr. He who does not perform Salat after coming to the fold of Islam, does not have a frontier which separates him from infidelity. Leaving Salat is like demolishing the wall that separates Islam from Kufr. Thus, we learn from this Hadith that leaving Salat is Kufr. Some `Ulama' are of the opinion that this injunction is for one who believes leaving Salat is permissible whereas the one who leaves it because of slackness is not a Kafir. Some scholars, however, think that if such a person does not repent, he is liable to Hadd, i.e., death punishment. There are other `Ulama' who think that rather than death punishment such a person should be subjected to corporal punishment till he starts offering Salat. This Hadith makes the importance of Salat in Islam abundantly clear.

Shaqiq bin `Abdullah (radiallahu anh) reported: The Companions of the Messenger of Allah (salallahu alayhi wa salam) did not consider the abandonment of any action as disbelief except neglecting Salat.
[At-Tirmidhi].

Commentary: The opinion of the Companions of the Prophet (salallahu alayhi wa salam) was based on the information contained in the Ahadith which have been mentioned above. They did not take the Ahadith which interpreted the leaving of Salat as Kufr mere scolding or reproof. They considered slackness and negligence in Salat as Kufr and apostasy and regarded Salat a symbol of Islam.

Abu Hurairah (radiallahu anh) reported: The Messenger of Allah (salallahu alayhi wa salalm) said, "The first of man's deeds for which he will be called to account on the Day of Resurrection will be Salat. If it is found to be perfect, he will be safe and successful; but if it is incomplete, he will be unfortunate and a loser. If any shortcoming is found in the obligatory Salat, the Glorious and Exalted Rubb will command to see whether His slave has offered any voluntary Salat so that the obligatory Salat may be made up by it. Then the rest of his actions will be treated in the same manner.''
[At-Tirmidhi].

Commentary: The rights mentioned in this Hadith are the Rights of Allah. The first of them for which one has to render account is Salat. In the rights of people, the first to be decided will be blood shed by a person of his fellow being. This Hadith also makes the following points:

1.Stress on the performance of the obligatory acts.

2.Inducement for voluntary prayers to make up the deficiency of the obligations.