From Sahih Muslim (Hadith 190):
It is reporter on the authority of Abu Huraira that the Messenger of Allah (may peace and blessings be upon him) observed:There came the people of Yemen who are soft of hearts, tender in feelings: the belief is that of the Yemenites, the sagacity is that of the Yemenites and the summit of unbelief is towards the East
Reference: Muslim 190