Musnad Ahmad 31:491

Muhammad ibn Bakr narrated to us, Sa'id informed us, from Qatadah, who said: My father narrated to us, and 'Affan narrated to us, Hammam narrated to us, Qatadah narrated to us, from Abu Nadrah, from Abu Sa'id al-Khudri, that the Messenger of Allah (peace and blessings of Allah be upon him) said: "If three are gathered, let one of them lead them, and the most entitled of them to the leadership is the one who is most proficient in reciting the Quran."