Sahih Muslim Book 4, Hadith Number 1751.

Chapter : Excellence of the reciting of the Qur’an by one who is more skilled and proficient before one who is inferior to him.

This Hadith has been narrated by A’mash with the same chain of transmitters but with this addition: “The Messenger of Allah (may peace be upon him) was on the pulpit when he asked me to recite to him.”