Sahih Bukhari Volume 3, Book 47, Hadith Number 744.
Narated By ‘Abdullah bin Abu Qatada Al-Aslami : That his father said, “One day I was sitting with some of the Prophet’s companions on the way to Mecca. Allah’s Apostle was ahead of us. All of my companions were in the state of Ihram while I was a non-Muhrim. They saw an onager while I was busy repairing my shoes, so they did not tell me about it but they wished I had seen it. By chance I looked up and saw it. So, I turned to the horse, saddled it and rode on it, forgetting to take the spear and the whip. I asked them if they could hand over to me the whip and the spear but they said, ‘No, by Allah, we shall not help you in that in any way.’ I became angry and got down from the horse, picked up both the things and rode the horse again. I attacked the onager and slaughtered it, and brought it (after it had been dead). They took it (cooked some of it) and started eating it, but they doubted whether it was allowed for them to eat it or not, as they were in the state of Ihram. So, we proceeded and I hid with me one of its fore-legs. When we met Allah’s Apostle and asked him about the case, he asked, ‘Do you have a portion of it with you?’ I replied in the affirmative and gave him that fleshy fore-leg which he ate completely while he was in the state of Ihram.