Sunan Ibn Majah, Chapter: The Chapters of Establishing the Prayer and the Sunnah Regarding Them

"The Messenger of Allah (saw) said: 'A man's prayer in his house is equal (in reward) to one prayer; his prayer in the mosque of the tribes is equal to twenty-five prayers; his prayer in the mosque in which Friday prayer is offered is equal to five-hundred prayers; his prayer in Aqsa Mosque is equal to fifty thousand prayers; his prayer in my mosque is equal to fifty thousand prayers; and his prayer in the Sacred Mosque is equal to one hundred thousand prayers."