Sahih Muslim
The Book of Faith (Kitab Al-Iman)
Book Number: 001 / Hadith Number: 84
It is narrated on the authority of Abu Huraira that the Messenger of Allah observed: There have come the people of Yemen; they are tender of hearts, the belief is that of the Yemenites, the understanding (of the faith) is that of the Yemenites and sagacity is that of the Yemenites.