The decontamination symbolism in the ab-zohr is a reflection of Zoroastrian cosmogony, wherein the primeval waters (the lower half of the sky, upon which the universe rests, and from which two rivers encircle the earth) fear pollution by humankind.
The decontamination symbolism within the ab-zohr reflects the Zoroastrian worldview, where the primordial waters (the lower half of the sky, supporting the universe, and from which two rivers encircle the earth) are intimidated by human activities that pollute their purity.