[Machine] The Quran was revealed in its entirety to the lower heaven, then it was revealed gradually over a period of twenty years. Allah, the Mighty and Majestic, says: {And they do not come to you with an argument except that We come to you with the truth and the best explanation} [Al-Furqan 33]. He also says: {And [mention] the Qur'an, for We have made it distinct, that you may recite it to the people in intervals. And We have sent it down progressively} [Al-Isra 106].
نَزَلَ الْقُرْآنُ جُمْلَةً إِلَى السَّمَاءِ الدُّنْيَا ثُمَّ نَزَلَ بَعْدَ ذَلِكَ فِي عِشْرِينَ سَنَةً وَقَالَ ﷻ {وَلَا يَأْتُونَكَ بِمَثَلٍ إِلَّا جِئْنَاكَ بِالْحَقِّ وَأَحْسَنَ تَفْسِيرًا} [الفرقان 33] قَالَ {وَقُرْآنًا فَرَقْنَاهُ لِتَقْرَأَهُ عَلَى النَّاسِ عَلَى مُكْثٍ وَنَزِّلْنَاهُ تَنْزِيلًا} [الإسراء 106]