Nasai

From this narration, it appears that the narrator of the hadith is Hazrat Ayman, who is a Companion (Sahabi), and the brother of Hazrat Usama radi Allahu anhu from his mother's side. However, this is a mistake of the narrator. The correct view is that Ayman was a Habashi (Abyssinian) from Makkah who was a Tabi‘i (Successor). It has been said that he was freed by Hazrat Zubair or Ibn Zubair, which is why this narration, being mursal (with a missing link) from a Tabi‘i, will be considered weak. Furthermore, it is also not acceptable as evidence because it contradicts authentic narrations, so it is not correct for the researcher of the book to declare it authentic. Even if, for the sake of argument, this Ayman is indeed the Companion Ayman, the narration is still disconnected (munqati‘), because Hazrat ‘Ata and Mujahid never met Hazrat Ayman, who was a Companion. Both of them belong to a later period, and these two elders are the ones who narrate this narration (about a dinar or ten dirhams). Therefore, whether Ayman is a Tabi‘i or a Companion, in both cases the chain is disconnected and unreliable—especially since the cutting of the hand for a lesser amount, such as three dirhams or a quarter of a dinar, is undoubtedly established from the Companions radi Allahu anhum.