Sahih Bukhari | Volume 3 | Hadith Number 768

Narrated by 'Abdullah bin 'Abbas
That he heard As-Sa'b bin Jaththama Al-Laithi, who was one of the companions of the Prophet, saying that he gave the meat of an onager to Allah's Apostle while he was at a place called Al-Abwa' or Waddan, and was in a state of Ihram. The Prophet did not accept it. When the Prophet 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. 747)