Ibn Abbas (may Allah be pleased with them both) narrates from Sa'b bin Jaththamah (may Allah be pleased with him) that he gave the Messenger of Allah (peace and blessings be upon him) a wild donkey as a gift while he (peace and blessings be upon him) was at al-Abwa or Waddan, and the Messenger of Allah (peace and blessings be upon him) returned it to him. When the Messenger of Allah (peace and blessings be upon him) saw what was in my face, he said: "We have returned it to you only because we are in the state of ihram."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9926