Musnad Ahmad 30:3004

Yahya ibn Sa'id narrated to us, from Ibn 'Awn, from Muhammad, from Abu Hurayrah, who said: Abu al-Qasim (peace and blessings of Allah be upon him) said: "The people of Yemen have come to you; they are the most tender-hearted. Faith is Yemeni, understanding of religion (fiqh) is Yemeni, and wisdom is Yemeni."