Musnad Ahmad 31:863

Safwan narrated to us, Anis ibn Abi Yahya narrated to us, from his father, from Abu Sa’id al-Khudri, that a man from Banu ‘Amr ibn ‘Awf and a man from Banu Khudrah disputed regarding the mosque which was founded on righteousness. The ‘Awfi said: "It is the Mosque of Quba." And the Khudri said: "It is the Mosque of the Messenger of Allah, may Allah bless him and grant him peace." They came to the Messenger of Allah, may Allah bless him and grant him peace, and asked him about that. He said: "It is this mosque of mine, and in that is much good."