Zayd bin Wahb (may Allah have mercy on him) says: A man came to Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) and said: O Commander of the Believers, I have left behind in Kufah a man who dictates mushafs from memory. Sayyiduna Umar (may Allah be pleased with him) became angry until his face swelled, then he asked: Who is he? He said: Abdullah bin Mas'ud. He said: May Allah's mercy be upon your father! And who could be more entitled to this honour than him? I heard the Messenger of Allah (peace and blessings be upon him) say: "Whoever would love to recite the Qur'an fresh, just as it was revealed, let him recite it according to the recitation of Ibn Umm Abd."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 8393