From Sahih Muslim (Hadith 3377):
Yahya b. Sa'id (Allah be pleased with him) reported:I said to Abu Salih: Did you hear Abu Huraira (Allah be pleased with him) making a mention of the excellence of prayer in the mosque of Allah's Messenger (ﷺ)? He said: No (I did not hear directly from Abu Huraira), but I heard Abdullah b. Ibrahlm b. Qariz; say that' he had heard from Abu Huraira (Allah be pleased with him) that Allah's Messenger (ﷺ) had said: Prayer in this mosque of mine is better than a thousand prayers. or. is like one thousand prayers observed in other mosques besides It, except that it be in al-Masjid al-Haram
Reference: Muslim 3377