"I arrived upon the Messenger of Allah (ﷺ) at Khaibar along with a group of the Ash'ari tribe. He gave us shared along with those that conquered it."

This Hadith is Hasan Sahih Gharib. This is acted upon according to some of the people of knowledge. Al-Awza'i said: "Whoever meets up with the Muslims before the horses, share is distributed, then he is given a share." And Buraid's (a narrator) Kunyah is Abu Buraidah and he is trustworthy. Sufyan Ath-Thawri, Ibn 'Uyainah and others report from him.