Mandaeans, also known as Mandaean Sabians or simply as Sabians, are an ethnoreligious group who are followers of Mandaeism. They believe that John the Baptist was the final and most important prophet. They may have been among the earliest religious groups to practice baptism, as well as among the earliest adherents of Gnosticism, a belief system of which they are the last surviving representatives today. The Mandaeans were originally native speakers of Mandaic, an Eastern Aramaic language, before they nearly all switched to Mesopotamian Arabic or Persian as their main language.

Persian Jews or Iranian Jews constitute one of the oldest communities of the Jewish diaspora. Dating back to the biblical era, they originate from the Jews who relocated to Iran during the time of the Achaemenid Persian Empire. Books of the Hebrew Bible bring together an extensive narrative shedding light on contemporary Jewish life experiences in ancient Persia; there has been a continuous Jewish presence in Iran since at least the time of Cyrus the Great, who led the Persian army's conquest of the Neo-Babylonian Empire and subsequently freed the Judahites from the Babylonian captivity.