Abu Dawud said “I recited to Muhammad bin Wazir Al Misri and said to him Bishr bin Bakr narrated it to you and Al Auza’i narrated it to us. And he said “At’a narrated it to us on the authority of Aus brother of ‘Ubadah bin Al Samit. The Prophet ﷺ gave him fifteen sa’s of wheat to feed sixty poor people.
Abu Dawud said At’a did not meet Aws (bin Al Samit) who was one of the people of Badr and died in the early days of Islam. This version is therefore, mursal (i.e., a successor narrated it directly from the Prophet ﷺ, the link of the Companions is missing). This has been narrated by Al Auza’i from At’a from Aus.