Musnad Ahmad 403:18

Abdullah ibn Ahmad said: Ishaq ibn Mansur informed us, he said: Abu al-Yaman al-Hakam ibn Nafi’ informed us, he said: Shu’ayb informed us, from al-Zuhri, he said: Ubayd Allah ibn Abdullah ibn Utbah ibn Mas’ud informed me, that Abdullah ibn Abbas informed him, that he heard al-Sa’b ibn Jaththama al-Laythi—and he was one of the companions of the Prophet, may Allah bless him and grant him peace—informing that he gifted a wild donkey to the Prophet, may Allah bless him and grant him peace, at al-Abwa’ or at Waddan, while the Prophet was in a state of ihram, so the Prophet returned it to him. Al-Sa’b said: When the Prophet, may Allah bless him and grant him peace, recognized in my face [the effect of] his returning my gift, he said: "It is not that we reject it from you, but we are in a state of ihram."