Narrated `Abdullah bin `Abbas: From As-Sa'b bin Jath-thama Al-Laithi that the latter presented an onager to Allah's Messenger (ﷺ) while he was at Al-Abwa' or at Waddan, and he refused it. On noticing the signs of some unpleasant feeling of disappointment on his (As-Sab's) face, the Prophet (ﷺ) said to him, "I have only returned it because I am Muhrim."
Source: sunnah.com
Other translations
Arabic
حَدَّثَنَا عَبْدُ اللَّهِ بْنُ يُوسُفَ، أَخْبَرَنَا مَالِكٌ، عَنِ ابْنِ شِهَابٍ، عَنْ عُبَيْدِ اللَّهِ بْنِ عَبْدِ اللَّهِ بْنِ عُتْبَةَ بْنِ مَسْعُودٍ، عَنْ عَبْدِ اللَّهِ بْنِ عَبَّاسٍ، عَنِ الصَّعْبِ بْنِ جَثَّامَةَ اللَّيْثِيِّ، أَنَّهُ أَهْدَى لِرَسُولِ اللَّهِ صلى الله عليه وسلم حِمَارًا وَحْشِيًّا، وَهْوَ بِالأَبْوَاءِ أَوْ بِوَدَّانَ فَرَدَّهُ عَلَيْهِ، فَلَمَّا رَأَى مَا فِي وَجْهِهِ قَالَ " إِنَّا لَمْ نَرُدَّهُ عَلَيْكَ إِلاَّ أَنَّا حُرُمٌ ".
sunnah.com