Musannaf Ibn Abi Shayba 22:395

Ibn Numayr narrated to us, from al-Ajalih, from Ibn Abza, from his father, who said: I heard Ubayy ibn Ka’b saying: The Messenger of Allah (ﷺ) said: "I have been commanded to recite the Qur’an to you." I said: "Did He name me to you?" He said: "Yes." Then Ubayy said: "By the grace of Allah and by His mercy, in that let them rejoice; it is better than what they accumulate."