Salah is based on Quran and Hadith.
1) Establishing Salah Develops Taqwa (Fear and Awareness of Allah)
ذَٰلِكَ الْكِتَابُ لَا رَيْبَ ۛ فِيهِ ۛ هُدًى لِلْمُتَّقِينَ الَّذِينَ يُؤْمِنُونَ بِالْغَيْبِ وَيُقِيمُونَ الصَّلَاةَ وَمِمَّا رَزَقْنَاهُمْ يُنْفِقُونَ
“This is the Book in which there is no doubt, a guidance for those who have Taqwa; who believe in the unseen, and who establish Salah, and spend out of what we have provided for them” (Surah Baqarah 2: 2-3)
2) Salah Is the Sign of a Believer.
وَالْمُؤْمِنُونَ وَالْمُؤْمِنَاتُ بَعْضُهُمْ أَوْلِيَاءُ بَعْضٍ ۚ يَأْمُرُونَ بِالْمَعْرُوفِ وَيَنْهَوْنَ عَنِ الْمُنْكَرِ وَيُقِيمُونَ الصَّلَاةَ وَيُؤْتُونَ الزَّكَاةَ وَيُطِيعُونَ اللَّهَ وَرَسُولَهُ ۚ أُولَـٰئِكَ سَيَرْحَمُهُمُ اللَّهُ ۗ إِنَّ اللَّهَ عَزِيزٌ حَكِيمٌ
“The believers, men and women, are protecting friends of one another; they enjoin good and forbid evil, and they establish Salah, and give Zakah, and obey Allah and His Messenger. Allah will have His Mercy on them, and surely, Allah is All-Mighty, All-Wise.” (Surah Tawba 9: 71)
3) Establishing Salah Leads to Allah’s Eternal Blessings.
فَمَا أُوتِيتُمْ مِنْ شَيْءٍ فَمَتَاعُ الْحَيَاةِ الدُّنْيَا ۖ وَمَا عِنْدَ اللَّهِ خَيْرٌ وَأَبْقَىٰ لِلَّذِينَ آمَنُوا وَعَلَىٰ رَبِّهِمْ يَتَوَكَّلُونَ وَالَّذِينَ يَجْتَنِبُونَ كَبَائِرَ الْإِثْمِ وَالْفَوَاحِشَ وَإِذَا مَا غَضِبُوا هُمْ يَغْفِرُونَ وَالَّذِينَ اسْتَجَابُوا لِرَبِّهِمْ وَأَقَامُوا الصَّلَاةَ وَأَمْرُهُمْ شُورَىٰ بَيْنَهُمْ وَمِمَّا رَزَقْنَاهُمْ يُنْفِقُونَ
“So whatever you have been given is but (a passing) enjoyment for this worldly life, but that which is with Allah is better and more lasting for those who believe and put their trust in their Lord. And those who avoid the great sins and lewdness, and when they are angry, they forgive. And those who answer the Call of their Lord, and perform the Salah, and who conduct their affairs by mutual consultation, and who spend of what We have bestowed on them.” (Surah Ash-Shura 42:36-38)
4) Those Who Pray Shall Have Nothing to Fear on the Day of Judgment.
إِنَّ الَّذِينَ آمَنُوا وَعَمِلُوا الصَّالِحَاتِ وَأَقَامُوا الصَّلَاةَ وَآتَوُا الزَّكَاةَ لَهُمْ أَجْرُهُمْ عِنْدَ رَبِّهِمْ وَلَا خَوْفٌ عَلَيْهِمْ وَلَا هُمْ يَحْزَنُونَ
“Truly, those who believe and do righteous deeds, and perform Salah, and give Zakah, they will have their reward with their Lord. On them shall be no fear, nor shall they grieve.” (Surah Baqarah 2:277)
5) Remain in Allah’s remembrance after prayer.
فَإِذَا قَضَيْتُمُ الصَّلَاةَ فَاذْكُرُوا اللَّهَ قِيَامًا وَقُعُودًا وَعَلَىٰ جُنُوبِكُمْ ۚ فَإِذَا اطْمَأْنَنْتُمْ فَأَقِيمُوا الصَّلَاةَ ۚ إِنَّ الصَّلَاةَ كَانَتْ عَلَى الْمُؤْمِنِينَ كِتَابًا مَوْقُوتًا
“When have finished performing the Salah, remember Allah standing, sitting, and reclining, but when you are free from danger, perform the Salah. Surely, Salah is enjoined on the believers at fixed times.” (Surah Nisaa 4:103)
6) Command to Pray with Congregation.
وَأَقِيمُوا الصَّلَاةَ وَآتُوا الزَّكَاةَ وَارْكَعُوا مَعَ الرَّاكِعِينَ
“And establish Salah and give Zakah, and bow down (in worship) along with those who bow down (in worship)” (Surah Baqarah 2:43)
7. Special Command Regarding Punctuality of Prayer.
حَافِظُوا عَلَى الصَّلَوَاتِ وَالصَّلَاةِ الْوُسْطَىٰ وَقُومُوا لِلَّهِ قَانِتِينَ
“Guard strictly the Salah, especially the middle Salah. And stand before Allah with obedience.” (Surah Baqarah 2:238)
8. Allah’s Help Comes Through Salah.
وَاسْتَعِينُوا بِالصَّبْرِ وَالصَّلَاةِ ۚ وَإِنَّهَا لَكَبِيرَةٌ إِلَّا عَلَى الْخَاشِعِينَ
“Seek help through patience and Salah; truly it is extremely difficult except for the humble true believers.” (Surah Baqarah 2:45)
يَا أَيُّهَا الَّذِينَ آمَنُوا اسْتَعِينُوا بِالصَّبْرِ وَالصَّلَاةِ ۚ إِنَّ اللَّهَ مَعَ الصَّابِرِينَ
“Oh you who believe! Seek help through patience and Salah. Truly, Allah is with those who are patient.” (Surah Baqarah 2:153)
9.) Special Emphasis on Friday Prayer.
يَا أَيُّهَا الَّذِينَ آمَنُوا إِذَا نُودِيَ لِلصَّلَاةِ مِنْ يَوْمِ الْجُمُعَةِ فَاسْعَوْا إِلَىٰ ذِكْرِ اللَّهِ وَذَرُوا الْبَيْعَ ۚ ذَٰلِكُمْ خَيْرٌ لَكُمْ إِنْ كُنْتُمْ تَعْلَمُونَ فَإِذَا قُضِيَتِ الصَّلَاةُ فَانْتَشِرُوا فِي الْأَرْضِ وَابْتَغُوا مِنْ فَضْلِ اللَّهِ وَاذْكُرُوا اللَّهَ كَثِيرًا لَعَلَّكُمْ تُفْلِحُونَ
“Oh you who believe! When the call is made for the Salah on Friday, come to the remembrance of Allah, and leave off business. That is better for you, if you only knew! And when the Salah has ended, you may disperse through the land, and seek the Bounty of Allah, and remember Allah much so that you may be successful.” (Surah Jumuah 62:09-10)
10) Shaytaan Tries His Best in Finding Ways to Take You Away from Salah
إِنَّمَا يُرِيدُ الشَّيْطَانُ أَنْ يُوقِعَ بَيْنَكُمُ الْعَدَاوَةَ وَالْبَغْضَاءَ فِي الْخَمْرِ وَالْمَيْسِرِ وَيَصُدَّكُمْ عَنْ ذِكْرِ اللَّهِ وَعَنِ الصَّلَاةِ ۖ فَهَلْ أَنْتُمْ مُنْتَهُونَ
“Shaytaan desires only to excite enmity and hatred between you with intoxicants and gambling, and hinder you from the remembrance of Allah, and from Salah. So will you then not abstain (from these evils)?” (Surah Maeda 5:91)
11) Prayer Protects Against Evils.
اتْلُ مَا أُوحِيَ إِلَيْكَ مِنَ الْكِتَابِ وَأَقِمِ الصَّلَاةَ ۖ إِنَّ الصَّلَاةَ تَنْهَىٰ عَنِ الْفَحْشَاءِ وَالْمُنْكَرِ ۗ وَلَذِكْرُ اللَّهِ أَكْبَرُ ۗ وَاللَّهُ يَعْلَمُ مَا تَصْنَعُونَ
“Recite that which has been revealed to you of the Book, and perform Salah. Verily, Salah prevents from lewdness and evils. And indeed, the remembrance of Allah (by you) is greatest. And Allah knows what you do.” (Surah Ankaboot 29:45)
12)Friendship Should Be with Those Who Pray.
إِنَّمَا وَلِيُّكُمُ اللَّهُ وَرَسُولُهُ وَالَّذِينَ آمَنُوا الَّذِينَ يُقِيمُونَ الصَّلَاةَ وَيُؤْتُونَ الزَّكَاةَ وَهُمْ رَاكِعُونَ
“Indeed, your protecting friend (Wali) is none other than Allah, His Messenger, and the Believers who establish Salah, and give Zakaat, and bow down (in prayer). (Surah Maeda 5: 55)
13) Allah’s Special Order to Women.
وَقَرْنَ فِي بُيُوتِكُنَّ وَلَا تَبَرَّجْنَ تَبَرُّجَ الْجَاهِلِيَّةِ الْأُولَىٰ ۖ وَأَقِمْنَ الصَّلَاةَ وَآتِينَ الزَّكَاةَ وَأَطِعْنَ اللَّهَ وَرَسُولَهُ ۚ إِنَّمَا يُرِيدُ اللَّهُ لِيُذْهِبَ عَنْكُمُ الرِّجْسَ أَهْلَ الْبَيْتِ وَيُطَهِّرَكُمْ تَطْهِيرًا
“And stay in your houses, and do not display yourselves like that of the times of ignorance, and perform Salah, and give Zakah, and obey Allah and His Messenger. Allah wishes only to remove uncleanness from you, Oh people of the House, and to purify you with a thorough purification.” (Surah Ahzaab 33:33)
14) Hypocrites Are Lazy in Salah.
إِنَّ الْمُنَافِقِينَ يُخَادِعُونَ اللَّهَ وَهُوَ خَادِعُهُمْ وَإِذَا قَامُوا إِلَى الصَّلَاةِ قَامُوا كُسَالَىٰ يُرَاءُونَ النَّاسَ وَلَا يَذْكُرُونَ اللَّهَ إِلَّا قَلِيلًا
“Verily, the hypocrites seek to deceive Allah, but it is He who deceives them; When they stand up for Salah, they stand with laziness, only to be seen by men; and they do not remember Allah but a little.” (Surah Nisaa 4:142)
15) Laziness in Salah Leads to Rejection of Sadaqah.
وَمَا مَنَعَهُمْ أَنْ تُقْبَلَ مِنْهُمْ نَفَقَاتُهُمْ إِلَّا أَنَّهُمْ كَفَرُوا بِاللَّهِ وَبِرَسُولِهِ وَلَا يَأْتُونَ الصَّلَاةَ إِلَّا وَهُمْ كُسَالَىٰ وَلَا يُنْفِقُونَ إِلَّا وَهُمْ كَارِهُونَ
“And nothing prevents their Sadaqah from being accepted from them, except that they disbelieve in Allah and in His Messenger, and that they do not come to Salah except in a lazy manner, and that they do not give Sadaqah except unwillingly.” (Surah Tawbah 9:54)
16) Leaving Salah Leads to Shirk.
مُنِيبِينَ إِلَيْهِ وَاتَّقُوهُ وَأَقِيمُوا الصَّلَاةَ وَلَا تَكُونُوا مِنَ الْمُشْرِكِينَ
“(And remain always) turning to Him (only), and be fearful and dutiful towards Him, and perform Salah and be not of those who commit Shirk.” (Surah Room 30: 31)
17) Previous Nations Were corrupted when Salah Was Left.
فَخَلَفَ مِنْ بَعْدِهِمْ خَلْفٌ أَضَاعُوا الصَّلَاةَ وَاتَّبَعُوا الشَّهَوَاتِ ۖ فَسَوْفَ يَلْقَوْنَ غَيًّا
“Then, there came after them a generation who gave up Salah and followed lusts; so they will be thrown in Hell.” (Surah Maryam 19: 59)