Musannaf Ibn Abi Shayba 3:5138

Ghundar narrated to us, from Shu'bah, from Sa'd ibn Ibrahim, that he heard Abu Salamah narrating to al-Agharr, that he heard Abu Hurayrah narrating that the Messenger of Allah (may Allah bless him and grant him peace) said: "A prayer in this mosque of mine is better than a thousand prayers in other than it from the mosques, except for the Ka'bah."