Alqamah (may Allah have mercy on him) says: A man came to Sayyiduna Umar (may Allah be pleased with him) and said: I have come to you with news of a man who dictates mushafs from memory. (The narrator says:) Sayyiduna Umar (may Allah be pleased with him) was alarmed and said in anger: Woe to you, look at what you are saying! And he became angry. The man said: I have brought you nothing but the truth. He said: Who is he? He said: Abdullah bin Mas'ud. He said: I know of no one more entitled to that than him, and I will tell you something about Abdullah: One night we stayed up talking in the house of Sayyiduna Abu Bakr (may Allah be pleased with him) about some matter that the Prophet (peace and blessings be upon him) needed. Then we came out, with the Messenger of Allah (peace and blessings be upon him) walking between me and Abu Bakr. When we reached the mosque, we saw a man reciting (the Qur'an), and the Prophet (peace and blessings be upon him) stood listening attentively to him. I said: O Messenger of Allah, it has grown late? He (peace and blessings be upon him) signalled to me with his hand to be quiet. He (the man praying) kept reciting, then he bowed, prostrated, and sat supplicating and seeking forgiveness, and the Prophet (peace and blessings be upon him) said: "Ask and you will be given." Then he said: "Whoever would love to recite the Qur'an fresh and moist, just as it was revealed, let him recite according to the recitation of Ibn Umm Abd." Then my companion and I knew that he was Abdullah (bin Mas'ud). When morning came, I went to him early to give him the glad tiding, and he said: Abu Bakr has already brought it (the glad tiding) before you. (Sayyiduna Umar (may Allah be pleased with him) says:) And whenever I tried to race ahead of him in any good deed, he always got there before me.
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 8388