That he heard As-Sa'b bin Jath-thama Al-Laithi, who was one of the companions of the Prophet, saying that he gave the meat of an onager to Messenger of Allah ﷺ while he was at a place called Al-Abwa' or Waddan, and was in a state of Ihram. The Prophet ﷺ did not accept it. When the Prophet ﷺ saw the signs of sorrow on As-Sa'b'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) (Using translation from Bukhārī 2596)
أَخْبَرَهُ أَنَّهُ سَمِعَ الصَّعْبَ بْنَ جَثَّامَةَ اللَّيْثِيَّ وَكَانَ مِنْ أَصْحَابِ النَّبِيِّ ﷺ يُخْبِرُ أَنَّهُ أَهْدَى لِلنَّبِيِّ ﷺ حِمَارَ وَحْشٍ بِالْأَبْوَاءِ أَوْ بِوَدَّانَ وَالنَّبِيُّ مُحْرِمٌ فَرَدَّهُ النَّبِيُّ ﷺ قَالَ الصَّعْبُ فَلَمَّا عَرَفَ النَّبِيُّ ﷺ فِي وَجْهِي رَدَّهُ هَدِيَّتِي قَالَ لَيْسَ بِنَا رَدٌّ عَلَيْكَ وَلَكِنِّي حُرُمٌ