Haj in the light of Quran 
Allah subhanahuta’la says:إِنَّ الصَّفَا وَالْمَرْوَةَ مِنْ شَعَائِرِ اللَّهِ فَمَنْ حَجَّ الْبَيْتَ أَوِ اعْتَمَرَ فَلَا جُنَاحَ عَلَيْهِ أَنْ يَطَّوَّفَ بِهِمَا وَمَنْ تَطَوَّعَ خَيْرًا فَإِنَّ اللَّهَ شَاكِرٌ عَلِيمٌ (158) “Verily!
As-Safa and Al-Marwah (two mountains in Makkah) are of the Symbols of Allah.  So it is not a sin on him who performs
 or Umrah (pilgrimage) of the House (the Ka’bah at Makkah) to perform the going (Tawaf) between them (As-Safa and Al-
). And whoever does good voluntarily, then verily, Allah is All-Recognizer, All-Knower (Al-Baqarah, Verse:158).
يَسْأَلُونَكَ عَنِ الْأَهِلَّةِ قُلْ هِيَ مَوَاقِيتُ لِلنَّاسِ وَالْحَجِّ وَلَيْسَ الْبِرُّ بِأَنْ تَأْتُوا الْبُيُوتَ مِنْ ظُهُورِهَا وَلَكِنَّ الْبِرَّ مَنِ اتَّقَى وَأْتُوا الْبُيُوتَ مِنْ أَبْوَابِهَا وَاتَّقُوا اللَّهَ لَعَلَّكُمْ تُفْلِحُونَ (189) “They ask you (Oh Mohammad sallallaahu alaihi wasallam about the new moons.  Say : These are signs to mark fixed periods of time for mankind for the pilgrimage…..” (Al-Baqarah, Verse:189).
وَأَتِمُّوا الْحَجَّ وَالْعُمْرَةَ لِلَّهِ “And perform properly (i.e. all the rituals according to the ways of Prophet Mohammad sallallaahu alaihi wasallam, the Hajj and Umrah (i.e. the pilgrimage to Makkah) for Allah……” (Surah Al-Baqarah, Verse-196)
الْحَجُّ أَشْهُرٌ مَعْلُومَاتٌ فَمَنْ فَرَضَ فِيهِنَّ الْحَجَّ فَلَا رَفَثَ وَلَا فُسُوقَ وَلَا جِدَالَ فِي الْحَجِّ وَمَا تَفْعَلُوا مِنْ خَيْرٍ يَعْلَمْهُ اللَّهُ وَتَزَوَّدُوا فَإِنَّ خَيْرَ الزَّادِ التَّقْوَى وَاتَّقُونِ يَا أُولِي الْأَلْبَابِ “The Hajj (pilgrimage) is (in) the well-known (lunar year) months (i.e. the 10^th month, the 11^th month and the first ten days of the
12^th month of the Islamic calendar i.e. two months and ten days).  So whosoever intends to perform Hajj therein by
assuming Ihram), then he should not have sexual relations (with his wife), nor commit sin, nor dispute unjustly during the
haj. And whatever good you do, (be sure) Allah knows it. And take a provision (with you) for the journey, but the best provision is At-Taqwa (piety, righteousness, etc.).  So fear Me, O men of understanding!” (Al-Baqarah, Verse : 197).
لَيْسَ عَلَيْكُمْ جُنَاحٌ أَنْ تَبْتَغُوا فَضْلًا مِنْ رَبِّكُمْ فَإِذَا أَفَضْتُمْ مِنْ عَرَفَاتٍ فَاذْكُرُوا اللَّهَ عِنْدَ الْمَشْعَرِ الْحَرَامِ وَاذْكُرُوهُ كَمَا هَدَاكُمْ وَإِنْ كُنْتُمْ مِنْ قَبْلِهِ لَمِنَ الضَّالِّينَ “There is no sin on you if you seek the Bounty of your Lord (during pilgrimage by trading, etc.). Then when you leave ‘Arafat, remember Allah (by glorifying His Praises, i.e. prayers and invocations, etc.) at the Mash’ar-il-Haram.  And remember Him (by invoking Allah for all good, etc.) as He has guided you, and verily, you were, before, of those who were astray.” (Al-Baqarah, Verse-198).
فَإِذَا قَضَيْتُمْ مَنَاسِكَكُمْ فَاذْكُرُوا اللَّهَ كَذِكْرِكُمْ آَبَاءَكُمْ أَوْ أَشَدَّ ذِكْرًا فَمِنَ النَّاسِ مَنْ يَقُولُ رَبَّنَا آَتِنَا فِي الدُّنْيَا وَمَا لَهُ فِي الْآَخِرَةِ مِنْ خَلَاقٍ So when you have accomplished your Manasik [i.e. Ihram, Tawaf of the Ka’bah and As-Safa and Al-Marwah, stay at ‘Arafat, Muzdalifah and Mina, Ramy of Jamarat, (stoning of the specified pillars in Mina), slaughtering of Hady (animal, etc)]. Remember Allah as you remember your forefathers or with a far more remembrance.  But of mankind there are some who say: “Our Lord! Give us (your Bounties) in this world!” and for such there will be no portion in the Hereafter.”  (Al-Baqarah, Verse-200).
إِنَّ أَوَّلَ بَيْتٍ وُضِعَ لِلنَّاسِ لَلَّذِي بِبَكَّةَ مُبَارَكًا وَهُدًى لِلْعَالَمِينَ “Verily, the first House (of worship) appointed for mankind was that at Bakkah (Makkah), full of blessing, and a guidance for Al-‘Alamin (the mankind and jinns).”  (Al-Imran, Verse-96).
فِيهِ آَيَاتٌ بَيِّنَاتٌ مَقَامُ إِبْرَاهِيمَ وَمَنْ دَخَلَهُ كَانَ آَمِنًا وَلِلَّهِ عَلَى النَّاسِ حِجُّ الْبَيْتِ مَنِ اسْتَطَاعَ إِلَيْهِ سَبِيلًا وَمَنْ كَفَرَ فَإِنَّ اللَّهَ غَنِيٌّ عَنِ الْعَالَمِينَ
“In it are manifest signs (for example), the Maqam (place) of Ibrahim (Abraham); whosoever enters it, he attains security.  And Haj (pilgrimage to Makkah) to the House (Kaba) is a duty that mankind owes to Allah, those who can afford the expenses (for one’s conveyance, provision and residence) and whoever disbelieves [i.e. denies Haj (pilgrimage to Makkah), then he is a disbeliever of Allah], then Allah stands not in need of any of trhe ‘Alamin (mankind and jinns).” (Al-Imran, Verse-97).
يَا أَيُّهَا الَّذِينَ آَمَنُوا أَوْفُوا بِالْعُقُودِ أُحِلَّتْ لَكُمْ بَهِيمَةُ الْأَنْعَامِ إِلَّا مَا يُتْلَى عَلَيْكُمْ غَيْرَ مُحِلِّي الصَّيْدِ وَأَنْتُمْ حُرُمٌ إِنَّ اللَّهَ يَحْكُمُ مَا يُرِيدُ “O you who believe! Fulfill (your) obligations. Lawful to you (for food) are all the beasts of cattle except that which will be announced to you (herein), game (also being unlawful when you assume Ihram for Haj or Umrah (pilgrimage). Verily, Allah commands that which He wills.” (Al-Ma’idah, Verse-01).
وَأَذَانٌ مِنَ اللَّهِ وَرَسُولِهِ إِلَى النَّاسِ يَوْمَ الْحَجِّ الْأَكْبَرِ أَنَّ اللَّهَ بَرِيءٌ مِنَ الْمُشْرِكِينَ وَرَسُولُهُ فَإِنْ تُبْتُمْ فَهُوَ خَيْرٌ لَكُمْ وَإِنْ تَوَلَّيْتُمْ فَاعْلَمُوا أَنَّكُمْ غَيْرُ مُعْجِزِي اللَّهِ وَبَشِّرِ الَّذِينَ كَفَرُوا بِعَذَابٍ أَلِيمٍ “And a declaration from Allah and His Messenger to mankind on the greatest day (the 10^th of Dhu Al-Hijjah – the 12rth month of Islamic calendar) that Allah is free from (all) obligations to the Mushrikun and so is His Messenger. So if you (Mushrikun) repent, it is better for you, but if you turn away, then know that you cannot escape (from the Punishment of) Allah. And give tidings (O Mohammad [sallallaahu alaihi wasallam]) of a painful torment to those who disbelieve.” (At-Taubah, Verse-03).
وَأَذِّنْ فِي النَّاسِ بِالْحَجِّ يَأْتُوكَ رِجَالًا وَعَلَى كُلِّ ضَامِرٍ يَأْتِينَ مِنْ كُلِّ فَجٍّ عَمِيقٍ “And proclaim to mankind the Hajj (pilgrimage). They will come to you on foot and on every lean camel; they will come from every deep and distant (wide) mountain highway (to perform haj). (Al-haj, Verse-27)