ʿAbdullah bin ʿAmr mentioned ʿAbdullah bin Masud and said, "I shall ever love that man, for I heard the Prophet ﷺ saying, 'Take (learn) the Qur'an from four: ʿAbdullah bin Masud, Salim, Muʿadh and Ubai bin Kaʿb.' "  

سَمِعْتُ النَّبِيَّ ﷺ يَقُولُ خُذُوا الْقُرْآنَ مِنْ أَرْبَعَةٍ مِنْ عَبْدِ اللَّهِ بْنِ مَسْعُودٍ وَسَالِمٍ وَمُعَاذٍ وَأُبَىِّ بْنِ كَعْبٍ  

Once ʿAbdullah bin Masʿud delivered a sermon before us and said, "By Allah, I learnt over seventy Suras direct from Messenger of Allah ﷺ . By Allah, the companions of the Prophet ﷺ came to know that I am one of those who know Allah's Book best of all of them, yet I am not the best of them." Shaqiq added: I sat in his religious gathering and I did not hear anybody opposing him (in his speech).  

وَاللَّهِ لَقَدْ أَخَذْتُ مِنْ فِي رَسُولِ اللَّهِ ﷺ بِضْعًا وَسَبْعِينَ سُورَةً وَاللَّهِ لَقَدْ عَلِمَ أَصْحَابُ النَّبِيِّ ﷺ أَنِّي مِنْ أَعْلَمِهِمْ بِكِتَابِ اللَّهِ وَمَا أَنَا بِخَيْرِهِمْ قَالَ شَقِيقٌ فَجَلَسْتُ فِي الْحِلَقِ أَسْمَعُ مَا يَقُولُونَ فَمَا سَمِعْتُ رَادًّا يَقُولُ غَيْرَ ذَلِكَ  

While we were in the city of Hims (in Syria), Ibn Masʿud recited Surat Yusuf. A man said to him), "It was not revealed in this way." Then Ibn Masʿud said, "I recited it in this way before Messenger of Allah ﷺ and he confirmed my recitation by saying, 'Well done!' " Ibn Masʿud detected the smell of wine from the man's mouth, so he said to him, "Aren't you ashamed of telling a lie about Allah's Book and (along with this) you drink alcoholic liquors too?" Then he lashed him according to the law.  

قَرَأْتُ عَلَى رَسُولِ اللَّهِ ﷺ فَقَالَ أَحْسَنْتَ وَوَجَدَ مِنْهُ رِيحَ الْخَمْرِ فَقَالَ أَتَجْمَعُ أَنْ تُكَذِّبَ بِكِتَابِ اللَّهِ وَتَشْرَبَ الْخَمْرَ فَضَرَبَهُ الْحَدَّ  

By Allah other than Whom none has the right to be worshipped! There is no Sura revealed in Allah's Book but I know at what place it was revealed; and there is no Verse revealed in Allah's Book but I know about whom it was revealed. And if I know that there is somebody who knows Allah's Book better than I, and he is at a place that camels can reach, I would go to him.  

وَاللَّهِ الَّذِي لاَ إِلَهَ غَيْرُهُ مَا أُنْزِلَتْ سُورَةٌ مِنْ كِتَابِ اللَّهِ إِلاَّ أَنَا أَعْلَمُ أَيْنَ أُنْزِلَتْ وَلاَ أُنْزِلَتْ آيَةٌ مِنْ كِتَابِ اللَّهِ إِلاَّ أَنَا أَعْلَمُ فِيمَ أُنْزِلَتْ وَلَوْ أَعْلَمُ أَحَدًا أَعْلَمَ مِنِّي بِكِتَابِ اللَّهِ تُبَلِّغُهُ الإِبِلُ لَرَكِبْتُ إِلَيْهِ  

I asked Anas bin Malik: "Who collected the Qur'an at the time of the Prophet ﷺ ?" He replied, "Four, all of whom were from the Ansar: Ubai bin Kaʿb, Muʿadh bin Jabal, Zaid bin Thabit and Abu Zaid."  

سَأَلْتُ أَنَسَ بْنَ مَالِكٍ ؓ مَنْ جَمَعَ الْقُرْآنَ عَلَى عَهْدِ النَّبِيِّ ﷺ قَالَ أَرْبَعَةٌ كُلُّهُمْ مِنَ الأَنْصَارِ أُبَىُّ بْنُ كَعْبٍ وَمُعَاذُ بْنُ جَبَلٍ وَزَيْدُ بْنُ ثَابِتٍ وَأَبُو زَيْدٍ  

When the Prophet ﷺ died, none had collected the Qur'an but four persons;: Abu Ad-Darda'. Muʿadh bin Jabal, Zaid bin Thabit and Abu Zaid. We were the inheritor (of Abu Zaid) as he had no offspring .  

مَاتَ النَّبِيُّ ﷺ وَلَمْ يَجْمَعِ الْقُرْآنَ غَيْرُ أَرْبَعَةٍ أَبُو الدَّرْدَاءِ وَمُعَاذُ بْنُ جَبَلٍ وَزَيْدُ بْنُ ثَابِتٍ وَأَبُو زَيْدٍ قَالَ وَنَحْنُ وَرِثْنَاهُ  

ʿUmar said, Ubai was the best of us in the recitation (of the Qur'an) yet we leave some of what he recites.' Ubai says, 'PI have taken it from the mouth of Messenger of Allah ﷺ and will not leave for anything whatever." But Allah said "None of Our Revelations do We abrogate or cause to be forgotten but We substitute something better or similar." 2.106  

عُمَرُ أُبَىٌّ أَقْرَؤُنَا وَإِنَّا لَنَدَعُ مِنْ لَحَنِ أُبَىٍّ وَأُبَىٌّ يَقُولُ أَخَذْتُهُ مِنْ فِي رَسُولِ اللَّهِ ﷺ فَلاَ أَتْرُكُهُ لِشَىْءٍ قَالَ اللَّهُ تَعَالَى {مَا نَنْسَخْ مِنْ آيَةٍ أَوْ نَنْسَأْهَا نَأْتِ بِخَيْرٍ مِنْهَا أَوْ مِثْلِهَا}