The name of the group derives from the term "Mandā d-Heyyi", which roughly means "Knowledge of Life". John the Baptist is a key figure in the religion, as an emphasis on baptism is part of their core beliefs. They are thought to be originally from Judea/Palestine and their anthropogeny appears Jewish and Gnostic. Mandaeans revere Adam, Abel, Seth, Enos, Noah, Shem, Aram, and especially John the Baptist. Significant amounts of original Mandaean Scripture, written in Mandaean Aramaic, survive in the modern era. The primary source text is known as the Genzā Rabbā and has portions identified by some scholars as being copied as early as the 2nd–3rd centuries. There is also the Qolastā, or Canonical Book of Prayer and the Mandaean Book of John (Sidra ḏ'Yahia).