It was narrated from Zahdam that:
some chicken was brought to AbuMusa and a man moved away form the people. He said: What is the matter with You? He said: I saw it eating something that I consider filthy, and I swore I would not eat it. Abu Musa said: Come and eat, for I saw the Messenger of Allah eating it. And he told him to offer45 expiation for his vow (Kafarat Al- Yamin)