كتاب الحج
15  
The Book of Pilgrimage
(85)
Chapter: The virtue of Al-Madinah and the Prophet's Prayer for it to be blessed. Its sanctity and the sanctity of its game and trees. The Boundaries of its sanctuary
(85)
باب فَضْلِ الْمَدِينَةِ وَدُعَاءِ النَّبِيِّ صلى الله عليه وسلم فِيهَا بِالْبَرَكَةِ وَبَيَانِ تَحْرِيمِها وَتَحْرِيمِ صَيْدِهَا وَشَجَرِهَا وَبَيَانِ حُدُودِ حَرَمِهَا
Sahih Muslim 1361 a

Rafi' b. Khadij reported Allah's Messenger (ﷺ) as saying:

Ibrahim declared Mecca as sacred and I declare sacred the area between its two stony grounds (lava lands by which he meant Medina).
وَحَدَّثَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، حَدَّثَنَا بَكْرٌ، - يَعْنِي ابْنَ مُضَرَ - عَنِ ابْنِ الْهَادِ، عَنْ أَبِي، بَكْرِ بْنِ مُحَمَّدٍ عَنْ عَبْدِ اللَّهِ بْنِ عَمْرِو بْنِ عُثْمَانَ، عَنْ رَافِعِ بْنِ خَدِيجٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ إِنَّ إِبْرَاهِيمَ حَرَّمَ مَكَّةَ وَإِنِّي أُحَرِّمُ مَا بَيْنَ لاَبَتَيْهَا ‏"‏ ‏.‏ يُرِيدُ الْمَدِينَةَ ‏.‏
Reference : Sahih Muslim 1361a
In-book reference : Book 15, Hadith 519
USC-MSA web (English) reference : Book 7, Hadith 3151
  (deprecated numbering scheme)