Sayyiduna Ibn Abbas (may Allah be pleased with them both) reported that Sayyiduna Sa'b bin Jaththamah (may Allah be pleased with him) told him that the Messenger of Allah (peace and blessings be upon him) passed by him at al-Abwa or Waddan, and he gave him (peace and blessings be upon him) a wild donkey as a gift, but he returned it to him. When the Messenger of Allah (peace and blessings be upon him) saw the dislike in his face, he said: "There is no rejection of you on our part; but I am in the state of ihram."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 9928