Akkadian God in the Enūma Eliš
As a God: Apsû was the primordial freshwater sea in Babylonian mythology, one of the first two Gods of creation along with the salt sea Tiāmat.
As terminology: prior to the myth of the Enūma Eliš, Apsû (Akkadian) / Abzu (Sumerian) was known as a non-anthropomorphic cosmological location— the very source of all fresh water on Earth—home to many gods, principally Ea (Akkadian) / Enki (Sumerian). The Apsû/Abzu also referred in some cases to water than can be accessed at the surface in order to pinch off clay or to catch fish— according to Jensen (Link). The Abzu/Apsû was also the name for tanks of holy purified water.
Thus the term is multifaceted. However, the anthropomorphic God Apsû of the Enūma Eliš was not worshipped in Mesopotamia, nor was he considered worthy of worship. Any worship would be wholly modern.
—How to use the internet archive Link
The abzu (Sumerian form) or apsû (Akkadian form) was a large underground body of water in Mesopotamian cosmic geography. It was the domain of the god Enki/Ea. The city of Babylon was said to have been built on top of the abzu, and the Sumerian myth Enki and Ninhursag describes that the first humans were created from clay taken from the top of the abzu.
From Gods Demons & Symbols of Ancient Mesopotamia by Jeremy Black & Antony Green [Internet Archive Link]
Although it can sometimes rain very hard in southern Mesopotamia, it was anciently believed that springs, wells, streams, rivers and lakes drew their water from and were replenished from a freshwater ocean which lay beneath the earth in the abzu (apst) or engur. (The salt sea, on the other hand, surrounded the earth.) The abzu was the particular realm and home of the wise god Enki (Ea), his wife Damgalnuna (Damkina) and his mother Nammu, and was also inhabited by a number of creatures subordinate to him (see Enki's creatures).
Enki was thought to have occupied the abzu since before the creation of mankind.
According to the Babylonian Epic of Creation, Apsû was the name of a primal creature, the lover of Tiāmat, and when Ea killed Apsû, he set up his home on the dead creature's body, whose name was henceforth transferred to Ea's residence. Marduk, as Ea's son, was called 'firstborn son of the aps‹'. Enki's temple at Eridu was known as E-abzu, 'Abzu temple'.
The underworld was located even further down, beneath the abzu. Since in some traditions it was necessary to cross a river (the Hubur) to reach the underworld, the river may sometimes have been identified with the abzu (see river of the underworld).
The term abzu/apsû was also used to designate a tank for holy water in a temple courtyard.
From A Dictionary of Ancient Near Eastern Mythology by Gwendolyn Leick [Internet Archive Link]
from Sumerian Abzu, which denotes the subterranean 'sweet water ocean or groundwater, also generally the marshland of southern Mesopotamia.
In this area where rainfall is rare and where the semi-floating reed-islands support a great variety of wild life, the fertile marshes were regarded as the source of abundance. In mythological terms the Apsu extended underneath the surface of the earth, into a watery depth.
Several literary texts express the creative potential of the Apsu's muddy moisture. In the Sumerian myth Enki and Ninmah it is the place where Nammu forms the first human being. The god Kullu was also made there, according to the enuma Am ritual. Furthermore, an anthropomorphic Apsu is called the begetter of the great gods' in the cosmogonic beginning of the Enuma elis (1, 59-78). In this composition the Apsu is inert and sleepy but finds his peace disturbed by the restless ways and clamour of the younger gods, the offspring of his union with another watery body, Tiamat. He decides to destroy them. The gods choose Ea as their champion and he puts a spell on Apsu, casting him into a deep sleep and 'killing him'. This death, however, does not annihilate the essence of the Apsu, it just renders him without any will of his own. Thereby the Apsu is contained underground and becomes the dwelling of Ea Enku, the 'Lord of the Apsu' One of the oldest sanctuaries in Mesopotamia was at the southern city of Eridu, which was apparently situated on a hillock surrounded by a lagoon. In historical times, the temple was known as E-abzu, 'the House of the Apsu', and dedicated to Enki. Other cult-centres seem to have had natural or artificial ponds or basins which represented the Apsu.
From A Handbook of Gods and Goddesses of the Ancient Near East by Douglas R Frayne and Johanna H Stuckey [Google Book Link]
Apsû(m) (Akk.), Abzu (Sum.)
Primeval deity of sweet (fresh) subterranean waters, which were the source of springs, lakes, rivers, and well water.
His consort was Ti'amat. The Enūma Eliš told how, in the beginning, the god Apsû(m), sweet waters, mingled with the goddess Ti'amat, salt waters. Another entity, Mummu, Apsû's minister or vizier, might also have been with them. The joining of the primordial pair begat a line of deities starting with Lahmu(m) and Lahamu(m) and fol-lowed, in sequence, by An-sar and Ki-Sar, Anu(m), Ea, and, finally, Marduk.
The younger gods were so rowdy and raucous that their parents could not get any sleep. Finally, Apsû(m) persuaded a reluctant Ti'amat that they should rid themselves of their noisy children. When the younger gods got wind of the plan, they quieted down until wise Ea thought of a solution. He put a magical sleeping spell on Apsû(m) and then, while Apsû(m) slept, Ea killed him. On Apsû(m)'s dead body Ea built his house at Eridu and called it
"Apsu(m)," the name of Ea's Eridu temple (E-Apsû) from then on. Marduk, Ea's son, was born in the Apsû(m). An Abzu/ Apsû(m) tank filled with holy water stood in most temple court-yards.
From Bad King, False King, True King: Apsû and His Heirs by Karen Sonik [JSTOR Link]
The problem of accurately pinpointing Apsû’s role and identity within Enuma elis, whether as monster or personified or deified subterranean waters, springs both from the shifting nature of his depiction in the narrative and from the writing of his name therein, which never includes the divine determinative that marks the gods proper within the text. Portrayed as an elemental entity at the opening of the epic as he mingles his waters with those of Tiamat, Apsû does not remain such for long. Once the first gods are generated from his intercourse with Tiamat, beginning the process of differentiation, Apsû himself seems to morph into a sort of proto-god, still not endowed with the dingir-determinative but newly provided with anthropomorphic features and with insignia reflecting his new rank and status: He is given both a voice and a mouth with which to speak (Ee I 35–36); a more or less anthropomorphic physical form (I 53–54), clothing or insignia including at least an agû, crown; and possibly also a riksu, sash or tie (I 67); melammu (I 68); and a rudimentary household of the type standard for the great gods, though here simply comprising his vizier or counselor Mummu (I 30–31). On the subject of Aprû’s state of dress, it is worth reiterating the association of clothing with life in Mesopotamian literature, specifically with civilized life. Thus, in well-known episodes from the SB Epic of Gilgames, Enkidu dons clothing as the second step in his transformation from wild proto-man to civilized man of the city (Gilg. SB II 34–35), while Gilgames, who dresses in lion skins during his wanderings in the wild, again dons his clean royal finery before returning to human civilization (XI 250–70). In the case of Apsû, his assumption of the agû may similarly signify his transformation into a more civilized and active entity, the direct result of his contribution to the differentiation and organization of the world through the generation of the gods.
From The Tablet of Destinies and the Transmission of Power in Enūma Eliš by Karen Sonik [PDF Link]
The opening lines of the epic describe the mingling of two primordial and el- emental entities, Apsû and Tiāmat, who generate the first gods and who seem to evolve thereby into active proto-deities, complete with at least semi-anthropomor- phic forms and divine powers and attributes. As the parents of all the gods, Apsû and Tiāmat may also be read as the first rulers of the text, legitimately endowed with divine authority over the gods. Apsû, as befits a king, stands at the head of a line of legitimate heirs, among them Lahmu and Lahamu, Anšar and Kišar, Anu, Ea, and ultimately Marduk, who comprise the great gods. He is also the apparent progenitor of a mass of unnamed and undifferentiated descendents, who comprise the lesser gods. Legitimate power, so far, is relatively concentrated: it is located in the hands of Apsû and Tiāmat and their rightful heirs. This situation, however, does not last.
[Footnote 6] Apsû and Tiāmat are not gods proper as has sometimes been suggested, ibid. Their names, unlike those of the rest of the gods in Enūma eliš, are never written with the divine determinative (Anšar alone is excepted, as his name begins with the dingir sign). Following the generation of the first gods from the mingling of their waters, however, Apsû and Tiāmat do seem to evolve into proto-deities, possibly as a result of the civilizing qualities of sexual intercourse [...]
[Footnote 7] Whether he is to be understood as the first king or ruler, Apsû is certainly the first major male authority figure to appear in Enūma eliš by virtue of his position as the father of all the gods. (Page 388)
The myth he appears in is one that justifies Marduk as chief deity and therefore legitimizes the government.
LW King Translation from 1902 — Link
Translation on Electronic Tools and Ancient Near East Archives (ETANA) — Link
Compiled translation primarily based on E.A Speiser — Link
E.A Speiser's translation is available in The Ancient Near East an Anthology of Texts and Pictures by James Pritchard page 28. — Link
None that we know of, but here is one of the ritual pools:
