Musnad Ahmad 30:297

Yahya narrated to us, from Yahya, Dhakwan Abu Salih narrated to me, from Ibrahim ibn Abdullah or Abdullah ibn Ibrahim—Yahya was in doubt—from Abu Hurairah, who said: 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 what is other than it, except for the Sacred Mosque (al-Masjid al-Haram)."