Musnad Ahmad 30:751

Zayd ibn al-Hubab narrated to us, Muhammad ibn Hilal al-Qurashi informed me, from his father, that he heard Abu Hurayrah saying: We were with the Messenger of Allah, may Allah bless him and grant him peace, in the mosque. When he stood up, we stood up with him. A Bedouin came to him and said: "Give me, O Muhammad." He said: So he said, "No, and I seek forgiveness from Allah." The Bedouin pulled him by his waist-wrapper, and scratched him. He said: They (the companions) intended to harm him. He said, "Leave him." He said: Then he gave him something. He said: And it was his oath to say, "No, and I seek forgiveness from Allah."