People excel over one another in faith, and the superiority of the people of Yemen in faith Sahih Muslim 53
Arabic hadith text
حَدَّثَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، أَخْبَرَنَا عَبْدُ اللَّهِ بْنُ الْحَارِثِ الْمَخْزُومِيُّ، عَنِ ابْنِ جُرَيْجٍ، قَالَ أَخْبَرَنِي أَبُو الزُّبَيْرِ، أَنَّهُ سَمِعَ جَابِرَ بْنَ عَبْدِ اللَّهِ، يَقُولُ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم "غِلَظُ الْقُلُوبِ وَالْجَفَاءُ فِي الْمَشْرِقِ وَالإِيمَانُ فِي أَهْلِ الْحِجَازِ "
Translation
It is reported on the authority of Jabir b. Abdullah that the Messenger of Allah (may peace and, blessings be upon him) observed
The callousness of heart and sternness is in the East and faith is among the people of the Hijaz.