Abzû

In Mesopotamian cosmogony Abzû is the primeval freshwater abyss that exists before the ordered heavens and earth. In the Babylonian Enūma Eliš tradition Apsû (fresh water) and Tiamat (salt sea) are the primordial waters that mix together; from their mingling the younger gods arise and the later ordered world comes into being. Abzû is also implicated in narratives such as the Atrahasis flood motif, where subterranean waters are part of the cosmological stock from which waters that produce a Flood derive. Locally, the god Enki/Ea is said to 'appear out of the abzû,' and Enki’s temple at Eridu was named E2-abzû ('house of the deep waters'), linking the cosmic origin role to cultic place.

Primary sources emphasize Abzû as a watery realm or material principle rather than a consistently anthropomorphic figure. In myths such as the Enūma Eliš Apsû is described as 'the freshwater ocean ... the first, the begetter,' a primordial aquatic presence. Temple and cult contexts further imagine the abzû as concrete installations — tanks of holy fresh water and the swamp at Eridu adjacent to E2-abzû — a sacred watery dwelling from which deities like Enki emerge rather than a standardized humanoid portrait.

As a cosmological principle, Abzû functions as the source of fresh water and a generative progenitor: its mixing with the salt sea (Tiamat) produces younger gods and sets conditions for creation. In narrative contexts (notably the Enūma Eliš) Apsû is portrayed with agency as a primordial being whose existence precedes created order and whose relations with younger gods precipitate divine activity. In cultic practice the abzû denotes holy water installations used for ritual washing and purification; there Abzû's 'ability' is manifested as purifying, life-giving water embedded in temple ritual rather than as a hostile supernatural force.