Musannaf Ibn Abi Shayba 27:859

Al-Fadl ibn Dukayn narrated to us, from Ibrahim ibn Nafi’, from al-Hasan ibn Muslim, from Tawus, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "I have indeed intended not to accept [a pledge or testimony] except from a Qurayshi, an Ansari, or a Thaqafi."