The significance of the mountain in history is that the Samaritans built their temple, a rival to the Jerusalem temple and built to the same design, on its slopes. Excavations have shown that their first temple was built in the mid-5th century BCE, that is roughly contemporarily with the work of Ezra and Nehemiah in Jerusalem. It was replaced by a larger one in the 3rd century, which was destroyed by the Jewish king John Hyrcanus in ca. 112-10 BCE, but though some Samaritans may have decided as a result to attend the Jerusalem temple instead (i.e., to become ‘Jews’), most continued to worship on the mountain (as John 4 testifies), though they were never permitted to rebuild the temple. To this day they celebrate Passover on Mount Gerizim.
In the text
In Deuteronomy and Joshua it figures in the ceremony of blessing and cursing prescribed in Deuteronomy 27, as the site where blessing is pronounced. If the variant reading in Deuteronomy 27:4 is correct, it is also the place where the law is inscribed and the first sacrifices in the promised land are carried out. There is clearly a connection between this reading and the siting of the Samaritan temple on Mount Gerizim, but it is disputed whether the text is simply a Samaritan reading favouring the temple, or whether the Samaritans chose Mount Gerizim because of its role in the text (Magnar Kartveit).
Kartveit, Magnar. The Origin of the Samaritans. Leiden: Brill, 2009.
Knoppers, Gary N. Jews and Samaritans: the Origins and History of their Early Relations. New York: Oxford University Press, 2013.
Magen, Y. ‘The Dating of the First Phase of the Samaritan Temple on Mount Gerizim in Light of the Archaeological Evidence.’ Pages 157-211 in Judah and the Judeans in the Fourth Century B.C.E. Edited by Oded Lipschits, Gary N. Knoppers, and Rainer Albertz. Winona Lake, IN: Eisenbrauns, 2007.