In the earliest recorded lists, Enki and Ninki were the immediate parents of Enlil, but beginning in the Ur III period onwards, a growing number of 'ancestors' separated them.
[15] Wilfred G. Lambert has suggested that the latter name had a different etymology, and due to the presence of an omittible g in spellings such as dEn-ki-ga-ke4 assumed that instead of ki, "earth", it was formed with the element kig, of unknown meaning.
[21] According to Christopher Metcalf, the tradition regarding Enlil's parentage which involved the Enki-Ninki deities is now considered conventional, though relevant sources remain difficult to interpret.
[2][b] Two sources which include both the pairs Enki and Ninki and An with either Urash or Ki, with the latter placed before them, are also known, and presumably reflect the belief that the coupling of earth and heaven preceded the emergence of the ancestors of Enlil.
[10] Wilfred G. Lambert suggested that an alternate interpretation of the lists might have been that each "generation" evolved from the previous one, with Enki and Ninki slowly morphing into Enlil and Ninlil, similarly with no implications of incest.
[1] A myth in which Enki and Ninki were banished to the underworld or fled there and found a new role there might have existed, though it is not directly preserved save for a possible allusion in an incantation.
[30] A single incantation places them in the Abzu,[31] which is presumed to be a part of a broader pattern of references to underworld deities instead dwelling there.
[1] The names of the primordial deities associated with Enlil could be invoked in exorcisms against evil spirits, though according to Wilfred G. Lambert relevant sources postdate the Old Babylonian period and might represent a tradition which only developed relatively late.
[20] However, according to Andrew R. George earlier examples also exist, and typically make Enki and Ninki the figures by which demons are forced to swear oaths in specific exorcisms.
[32] Ninki alone is mentioned in the oath formula on Eannatum's Stele of the Vultures, where it is stated that if Umma were to break the promises made, this goddess would punish the city.
[39] "Ninki" is also attested in Ebla as a part of the phrase nin-ki kalam timki, “lady of the country”, possibly the epithet of a goddess, and as a title of Tilut, one of the wives of the vizier Ibrium.
[20] However, Gonzalo Rubio lists a single possible Ur III example, a fragment from Nippur, N-T545 (A 33647), which might be either an incantation or a literary text.
[42] He set out these gifts (...), for Enki and Ninki, Enmul and Ninmul, Endukuga and Nindukuga, Endašurima and Nindašurimma, Enmu-utula,[c] Enmešarra, the female and male ancestors of Enlil.
[44] Enumerations of pairs of ancestors of Enlil also occur in laments dedicated to him, which commonly include long lists of various deities associated with him.
[45] An unfinished text of this variety known from the Old Babylonian tablet CBS 10417[46] mentions a gift he received from the pairs Enki and Ninki and Enul and Ninul.
[51] A prayer to Shamash and the “gods of the night” invokes Enki and Ninki alongside Alala and Belili,[52] a pair of primordial deities belonging to the family tree of Anu.
[17] The latter source specifically refers to a funerary offering made in Tašrītu, and lists Lugaldukuga alongside the pair Enki and Ninki as its recipient.
[6] In An = Anum, Enšar and Ninšar occur among ancestors of Anu, and additionally another listed pair, Enuruulla and Ninuruulla, follows the en-nin pattern.
[85] Karel van der Toorn argues that the Ugaritic god Ilib can be considered a representation of a theological idea analogous to the ancestors of Enlil.