Bulugh al-Maram, Book 6, Hadith 798 (English) ⓘ

Ibn Az-Zubair (RAA) narrated that the Messenger of Allah said: "Offering prayer in my mosque (in Madinah) is better than one thousand prayers elsewhere, save for those offered prayer in al-Masjid al-Haram (in Makkah). And prayer offered in al-Masjid al-Haram is better than prayer offered in my mosque by one hundred prayers." Related by Ahmad and Ibn Hibban graded it as Sahih.

وَعَنِ اِبْنِ اَلزُّبَيْرِ رَضِيَ اَللَّهُ عَنْهُمَا قَالَ: قَالَ رَسُولُ اَللَّهِ ‏- صلى الله عليه وسلم ‏-{ صَلَاةٌ فِي مَسْجِدِي هَذَا أَفْضَلُ مِنْ أَلْفِ صَلَاةٍ فِيمَا سِوَاهُ إِلَّا اَلْمَسْجِدَ اَلْحَرَامَ, وَصَلَاةٌ فِي اَلْمَسْجِدِ اَلْحَرَامِ أَفْضَلُ مِنْ صَلَاةٍ فِي مَسْجِدِي بِمِائَةِ صَلَاةٍ } رَوَاهُ أَحْمَدُ, وَصَحَّحَهُ اِبْنُ حِبَّانَ 1‏.‏ ‏1 ‏- صحيح.‏ رواه أحمد ( 4 / 5 )‏، وابن حبان ( 1620 )‏.‏