Sunan Ibn Majah, Hadith 4304 ⓘ
It was narrated from Anas that the Messenger of Allah said: “The distance between the two ends of my Cistern is like the distance between San’a and Al-Madinah,’ or ‘between Al-Madinah and ‘Amman.’”
حَدَّثَنَا نَصْرُ بْنُ عَلِيٍّ، حَدَّثَنَا أَبِي، حَدَّثَنَا هِشَامٌ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ، قَالَ قَالَ رَسُولُ اللَّهِ ـ صلى الله عليه وسلم ـ " مَا بَيْنَ نَاحِيَتَىْ حَوْضِي كَمَا بَيْنَ صَنْعَاءَ وَالْمَدِينَةِ أَوْ كَمَا بَيْنَ الْمَدِينَةِ وَعَمَّانَ " .
also referenced under: Book 37, Hadith 4446 (In-Book) & Volume 5, Book 37, Hadith 4304 (DarusSalam)