The Messenger of Allah ﷺ said, "A prayer in this mosque of mine is better than a thousand prayers in any other mosque, except the Sacred Mosque, and a prayer in the Sacred Mosque is better than a hundred prayers in this one."
قال رسول الله ﷺ: صلاة في مسجدي هذا أفضل من ألف صلاة فيما سواه من المساجد إلا المسجد الحرام، وصلاة في المسجد الحرام أفضل من مائة صلاة في هذا.
Ahmad narrated it (16117), and Bazzar - Kashf Astar - (425), both through the route of Hammad bin Zayd, who said, Habib al-Muallim narrated to us, from Ata bin Abu Rabah, from Abdullah bin Zubayr, and he mentioned something similar. Ibn Hibban graded it sahih (1620), narrating it through this same route. Its chain is hasan because of Habib al-Muallim, for although he is among the narrators found in all the major collections, there is disagreement about him. A group of scholars deemed him reliable, while Nasai criticized him, though he considered his hadith to be hasan. Haythami said in Majma (4/4-5), "Ahmad, Bazzar, and Tabarani in Kabir narrated it in a manner similar to Bazzar's version, and the narrators of Ahmad and Bazzar are the narrators found in Sahih [collections]." The hadith has other chains as well, and the one I have mentioned is the best of them.As for his statement, "and prayer in Masjid al-Haram is superior by a hundred times," Ata said, "So it is as if it were a hundred thousand times." Abu Dawud Tayalisi narrated this (1364) through the route of Rabi bin Sabih, who said, I heard Ata bin Abu Rabah say, "While Ibn Zubayr was delivering a sermon to us, he said..." and he mentioned the hadith. In it he said, I said, "O Abu Muhammad, this superiority that you mention regarding Masjid al-Haram, does it apply to it alone, or to the entire sacred precinct?" He said, "No, rather it applies to the entire sacred precinct, for the whole sacred precinct is a masjid."End of quotation. As for Rabi bin Sabih, with a fatha on the letter sad, there is disagreement about him. Ibn Saad deemed him daif, while others regarded him as acceptable, among them Ahmad, Ibn Main, Abu Zura, Abu Hatim, Ibn Adi, and others.