In Sethian Gnostic texts, Yesseus Mazareus Yessedekeus is the personification of the Living Water. He is mentioned in the Nag Hammadi tractates of the Holy Book of the Great Invisible Spirit, Zostrianos, and Apocalypse of Adam.
Meyer (2007) gives the etymology of the Yesseus Mazareus Yessedekeus as follows.
In contrast, Lofts (2010) connects Mazareus with Mazzaroth and considers Yessedekeus to be cognate with Sadducee, in turn derived from Yu/Yu (an epithet for the divine) and the root , (to be right, just). Lofts also propose that the name Yessedekeus is also found in Mandaeism in the form of Yuzaá¹Âaq, an epithet for Manda d-Hayyi.
In Mandaeism, the uthra (celestial spirit) Piriawis Ziwa is the personification of the heavenly river of living water. Qulasta prayers and mention Piriawis Ziwa and Piriafil Malaka together as uthras.
In Mandaean scriptures such as the Ginza Rabba, (pronounced ) is mentioned as the personification of the Euphrates, which is considered to be the earthly manifestation of the heavenly yardna or flowing river (similar to the Yazidi concept of Lalish being the earthly manifestation of its heavenly counterpart).