Hadith 5:778
'Affan narrated to us, from Hammad ibn Salamah, from Humayd, from al-Hasan, from Uthman ibn Abi al-'As, that the delegation of Thaqif came to the Messenger of Allah, may Allah bless him and grant him peace. They stipulated to him that they would not be gathered (for military service), that they would not be taxed (tithed), and that no one other than themselves would be appointed over them.
حدثنا عفان عن حماد بن سلمة عن حميد عن الحسن عن عثمان بن أبي العاص أن وفد ثقيف قدموا على رسول الله صلى الله عليه وسلم فاشترطوا عليه أن لا يحشروا ولا يعشروا ولا يستعمل عليهم غيرهم