Allah the Exalted said:
رياض الصالحينAbū Zakariyyā Muḥyī al-Dīn Yaḥyā ibn Sharaf al-Nawawī١٩٣ - باب الأمر بالمحافظة على الصلوات المكتوبات والنهي الأكيد والوعيد الشديد في تركهن
١٩٣ - باب الأمر بالمحافظة على الصلوات المكتوبات والنهي الأكيد والوعيد الشديد في تركهن
Maintain with care the [obligatory] prayers and [in particular] the middle [i.e., ʿaṣr] prayer and stand before Allāh, devoutly obedient.
ۚ
And when the inviolable months1 have passed, then kill the polytheists wherever you find them and capture them and besiege them and sit in wait for them at every place of ambush. But if they should repent, establish prayer, and give zakāh, let them [go] on their way. Indeed, Allāh is Forgiving and Merciful.
وعن ابن مسعود - ﵁ - قال: سألت رَسُول اللهِ - ﷺ - أيُّ الأعْمَالِ أفْضَلُ؟ قَالَ: «الصَّلاَةُ عَلَى وَقْتِهَا» قلتُ: ثُمَّ أيٌّ؟ قَالَ: «بِرُّ الوَالِدَيْنِ» قلتُ: ثُمَّ أيٌّ؟ قَالَ: «الجِهَادُ في سَبِيلِ اللهِ». متفقٌ عَلَيهِ.
Ibn Mas'ud (may Allah be pleased with him) reported: I asked the Messenger of Allah ﷺ, "Which deed is best?" He said: "Prayer at its proper time." I said, "Then which?" He said: "Dutifulness to one's parents." I said, "Then which?" He said: "Striving in the path of Allah (jihad)." Agreed upon.
وعن ابن عمر ﵄، قَالَ: قال رَسُول اللهِ - ﷺ: «بُنِيَ الإسْلامُ عَلَى خَمْسٍ: شَهَادَةِ أَنْ لاَ إلهَ إلاَّ اللهُ، وَأنَّ مُحَمَّدًا رَسُولُ اللهِ، وَإِقَامِ الصَّلاَةِ، وَإِيتَاءِ الزَّكَاةِ، وَحَجِّ البَيْتِ، وَصَوْمِ رَمَضَانَ». متفقٌ عَلَيهِ.
Ibn 'Umar (may Allah be pleased with them both) reported that the Messenger of Allah ﷺ said: "Islam is built upon five: the testimony that there is no god but Allah and that Muhammad is the Messenger of Allah, the establishment of prayer, the giving of zakat, the pilgrimage to the House, and fasting in Ramadan." Agreed upon.
وعنه، قَالَ: قال رَسُول اللهِ - ﷺ: «أُمِرْتُ أَنْ أُقَاتِلَ النَّاسَ حَتَّى يَشْهَدُوا أَنْ لاَ إلهَ إلاَّ اللهُ، وأنَّ مُحَمَّدًا رَسُولُ اللهِ، وَيُقِيمُوا الصَّلاَةَ، وَيُؤْتُوا الزَّكَاةَ، فَإذَا فَعَلُوا ذَلِكَ، عَصَمُوا مِنِّي دِمَاءهُمْ وَأَمْوَالَهُمْ، إلاَّ بِحَقِّ الإسْلاَمِ، وَحِسَابُهُمْ عَلَى اللهِ». متفقٌ عَلَيهِ.
He also reported that the Messenger of Allah ﷺ said: "I have been commanded to fight the people until they testify that there is no god but Allah and that Muhammad is the Messenger of Allah, and they establish the prayer and give the zakat. If they do that, their blood and wealth are protected from me, except by the right of Islam, and their reckoning rests with Allah." Agreed upon.
وعن معاذٍ - ﵁ - قَالَ: بَعثنِي رَسُولُ اللهِ - ﷺ - إلى اليَمَنِ، فَقَالَ: «إنَّكَ تَأْتِي قَوْمًا مِنْ أَهْل الكِتَابِ، فَادْعُهُمْ إلى شَهَادَةِ أَنْ لاَ إلهَ إلاَّ اللهُ، وأنِّي رَسُولُ اللهِ، فَإنْ هُمْ أطاعُوا لِذلِكَ، فَأعْلِمْهُمْ أنَّ اللهَ تَعَالَى افْتَرَضَ عَلَيْهِمْ خَمْسَ صلَوَاتٍ فِي كُلِّ يَومٍ وَلَيلَةٍ، فَإنْ هُمْ أطَاعُوا لِذَلِكَ، فَأعْلِمْهُمْ أنَّ اللهَ تَعَالَى افْتَرَضَ عَلَيْهِمْ صَدَقَةً تُؤخَذُ مِنْ أغْنِيَائِهِمْ فَتُرَدُّ عَلَى فُقَرَائِهِمْ، فَإنْ هُمْ أطَاعُوا لِذلِكَ، فَإيَّاكَ وَكَرَائِمَ أمْوَالهِمْ، واتَّقِ دَعْوَةَ المَظْلُومِ، فَإنَّهُ لَيْسَ بَينَهَا وبَيْنَ اللهِ حِجَابٌ». متفقٌ عَلَيهِ.
Mu'adh (may Allah be pleased with him) reported: The Messenger of Allah ﷺ sent me to Yemen and said: "You are coming to a people from the People of the Book, so call them to testify that there is no god but Allah and that I am the Messenger of Allah. If they obey you in that, then inform them that Allah the Exalted has made obligatory upon them five prayers in every day and night. If they obey you in that, then inform them that Allah the Exalted has made obligatory upon them a charity to be taken from their rich and returned to their poor. If they obey you in that, then beware of taking the most prized portions of their wealth, and fear the supplication of the wronged, for there is no veil between it and Allah." Agreed upon.
وعن جابرٍ - ﵁ - قال: سمعت رَسُول اللهِ - ﷺ - يقول: «إنَّ بَيْنَ الرَّجُلِ وَبَيْنَ الشِّرْكِ والكُفْرِ، تَرْكَ الصَّلاَةِ». رواه مُسلِم.
Jabir (may Allah be pleased with him) reported: I heard the Messenger of Allah ﷺ saying: "Between a man and polytheism and disbelief stands the abandonment of prayer." Narrated by Muslim.
وعن بُرَيْدَة - ﵁ - عن النبيِّ - ﷺ - قَالَ: «العَهْدُ الَّذِي بَيْنَنَا وَبَيْنَهُمْ الصَّلاَةُ، فَمَنْ تَرَكَهَا فَقَدْ كَفَرَ». رواه التِّرمِذِيُّ، وَقَالَ: «حَدِيثٌ حَسَنٌ صحيح».
Buraydah (may Allah be pleased with him) reported from the Prophet ﷺ that he said: "The covenant between us and them is prayer; so whoever abandons it has indeed disbelieved." Narrated by al-Tirmidhi, who said: "A good and sound hadith."
وعن شقِيق بن عبدِ الله التَّابِعيِّ المتفق عَلَى جَلاَلَتِهِ ﵀، قَالَ: كَانَ أصْحَابُ محَمَّدٍ - ﷺ - لا يَرَوْنَ شَيْئًا مِنَ الأعْمَالِ تَرْكُهُ كُفْرٌ غَيْرَ الصَّلاَةِ. رَوَاهُ التِّرمِذِيُّ في كِتابِ الإيمان بإسنادٍ صحيحٍ.
Shaqiq ibn 'Abd Allah—the Successor whose eminence is agreed upon (may Allah have mercy on him)—reported: The Companions of Muhammad ﷺ did not regard the abandonment of any deed as disbelief other than prayer. Al-Tirmidhi narrated it in the Book of Faith with a sound chain.
وعن أبي هريرة - ﵁ - قَالَ: قال رَسُول اللهِ - ﷺ: «إنَّ أوَّلَ مَا يُحَاسَبُ بِهِ العَبْدُ يَوْمَ القِيَامَةِ مِنْ عَمَلِهِ صَلاَتُهُ، فَإنْ صَلَحَتْ، فَقَدْ أفْلَحَ وأَنْجَحَ، وَإنْ فَسَدَتْ، فَقَدْ خَابَ وَخَسِرَ، فَإنْ انْتَقَصَ مِنْ فَرِيضَتِهِ شَيْءٌ، قَالَ الرَّبُ - ﷿: انْظُرُوا هَلْ لِعَبدي من تَطَوُّعٍ، فَيُكَمَّلُ مِنْهَا مَا انْتَقَصَ مِنَ الفَرِيضَةِ؟ ثُمَّ تَكُونُ سَائِرُ أعْمَالِهِ عَلَى هَذَا». رواه التِّرمِذِيُّ، وَقَالَ: «حَدِيثٌ حَسَنٌ».
Abu Hurayrah (may Allah be pleased with him) reported that the Messenger of Allah ﷺ said: "The first thing for which the servant will be brought to account on the Day of Resurrection out of his deeds is his prayer. If it is sound, he has succeeded and prospered; but if it is corrupt, he has failed and lost. If anything is found wanting in his obligatory prayers, the Lord (Mighty and Majestic) will say: 'Look whether My servant has any voluntary prayers,' so that whatever is deficient in the obligatory prayers may be completed from them. Then the rest of his deeds will be dealt with in the same way." Narrated by al-Tirmidhi, who said: "A good hadith."