He heard the Messenger of Allah ﷺ say, "The testimony of a bedouin against a town-dweller is not permissible."
حدثنا حرملة بن يحيى حدثنا عبد الله بن وهب أخبرني نافع بن يزيد عن ابن الهاد عن محمد بن عمرو بن عطاء عن عطاء بن يسار
أنه سمع رسول الله ﷺ يقول لا تجوز شهادة بدوي على صاحب قرية
Its isnad is sahih. Abu Dawud transmitted it in "Judgments," chapter "Testimony of the Bedouin against the People of the Towns," no. 3602, from the hadith of Ibn Wahb, through him, and Ibn Jarud graded it sahih, no. 1009.