It wasnarrated from Anas that the Messenger of Allah (ﷺ) said:
"Thedistance between the two ends of my Cistern is like the distancebetween San'a and Al-Madinah,' or 'between Al-Madinah and'Amman.'"
English reference: Vol. 5, Book 37, Hadith 4304
Arabic reference: Book 37, Hadith 4446