It is narrated from Abu Huraira (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "The people of Yemen will come to you; they are soft-hearted, and the coverings of their hearts are delicate. Faith is of the Yemenis, and wisdom is also of the Yemenis."
Hadith Referenceمسند الإمام الشافعي / كتاب فضائل قريش وغيرهم وأبواب متفرقة / 1789
Hadith Takhrijاخرجه البخاري، المغازی، باب قدوم الاشعريين واهل اليمن (4388) ، (3301) ومسلم، الایمان، باب تفاضل اهل الايمان فيه ورجحان اهل اليمن فيه (52)۔