The Qur'an names the Sabians as a People of the Book. According to some interpretations, the term refers to the Mandaens. From what I've read, the Mandaens call themselves the "Sons of Seth" and reject most of the major Islamic prophets (Abraham, Moses, Jesus, Muhammad, etc.), and their dualistic/gnostic understanding of God is a little strange compared to the other Abrahamic faiths. The appellation just doesn't seem to fit. Is there another explanation?