Sayyiduna Ammar bin Yasir (may Allah be pleased with him) narrates: The Prophet (peace and blessings be upon him) would not eat any gift until he instructed the person who brought it to eat some of it himself; this was because of the goat that was given to him as a gift at Khaybar.
Al-Bazzar recorded it from his teacher Ibrahim bin Abdullah al-Makhrami, whom al-Isma'ili declared thiqah (trustworthy) and al-Daraqutni declared da'if (weak); its chain also contains a narrator whom I do not know. (Allamah al-Haythami says:) I say: Before this, in the chapter on the Battle of Khaybar, the mursal narration transmitted by Urwah has already passed.