Musnad Ahmad 30:3145

'Abd al-Rahman narrated to us, from Sufyan, from Salih, the freed slave of al-Taw'amah, who said: I heard Abu Hurayrah saying: The Messenger of Allah (peace and blessings of Allah be upon him) said: "A prayer in this mosque of mine is better—or more excellent—than a thousand prayers in any other mosque, except for the Sacred Mosque (al-Masjid al-Haram)."