The Book of Prayers (Kitab Al-Salat)
Muslim :: Book 4 : Hadith 1747
Anas reported Allah's Messenger (may peace be upon him) as saying to Ubayy b. Ka'b: Allah has commanded me to recite the Qur'an to you. He said: Did Allah mention me to you by name? He (the Holy Prophet) said: Allah made a mention of your name to me. (On hearing this) Ubayy b. Ka'b wept.