Musnad Ahmad 30:605

'Abd al-Razzaq narrated to us, Hisham ibn Hassan informed us, from Muhammad, who said: I heard Abu Hurayrah saying: When "When the victory of Allah has come and the conquest" was revealed, the Prophet, may Allah bless him and grant him peace, said: "The people of Yemen have come to you; they are the most tender-hearted. Faith is Yemeni, jurisprudence is Yemeni, and wisdom is Yemeni."