Abu Qasim ﷺ said, "The people of Yemen have come to you. They are the most tender-hearted. Faith is Yemeni, understanding is Yemeni, and wisdom is Yemeni."
حدثنا يحيى بن سعيد عن ابن عون عن محمد
قال أبو القاسم ﷺ أتاكم أهل اليمن هم أرق أفئدة الإيمان يمان والفقه يمان والحكمة يمانية
Its chain of transmission is sahih. It is found in Bukhari 5/219, in the Book of Military Expeditions, chapter on the arrival of the Ashariyyin, in Muslim 1/73, and in Tirmidhi 4/276, number 3935, where he said it is hasan sahih.