Sahih Muslim , Book 43, Hadith 58 (In-Book) ⓘ
Anas b. Milik reported Allah's Messenger as saying: There would be such a vast distance between the sides of my Cistern as it is between Sana' and Medina.
وَحَدَّثَنَا عَاصِمُ بْنُ النَّضْرِ التَّيْمِيُّ، وَهُرَيْمُ بْنُ عَبْدِ الأَعْلَى، - وَاللَّفْظُ لِعَاصِمٍ - حَدَّثَنَا مُعْتَمِرٌ، سَمِعْتُ أَبِي، حَدَّثَنَا قَتَادَةُ، عَنْ أَنَسِ بْنِ مَالِكٍ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " مَا بَيْنَ نَاحِيَتَىْ حَوْضِي كَمَا بَيْنَ صَنْعَاءَ وَالْمَدِينَةِ " .
also referenced under: Hadith 2303 (Reference) & Book 30, Hadith 5708 (USC-MSA)