Sahih Bukhari, Chapter: Gifts, The superiority of giving and extortion of

That he heard As-Sab bin Jaththama Al-Laithi, who was one of the companions of the Prophet (SAW), saying that he gave the meat of an onager to Allah's Apostle (SAW) while he was at a place called Al-Abwa or Waddan, and was in a state of Ihram. The Prophet (SAW) did not accept it. When the Prophet (SAW) saw the signs of sorrow on As-Sab's face because of not accepting his present, he said (to him), "We are not returning your present, but we are in the state of Ihram." (See Hadith No. 758)