Qos (Edomite: 𐤒𐤅𐤎Qāws, laterQôs;[1]Hebrew:קוֹסQōs)[2] alsoQaus (Akkadian:𒋡𒍑Qa-uš), orKoze (Greek: KωζαιKōzai) was thenational god of theEdomites.[3] He was theIdumean structural parallel toYahweh. The name occurs only twice in theOld Testament (if a possible allusion in an otherwise corrupted text in theBook of Proverbs is excluded)[4] in theBook of Ezra andNehemiah as an element in a personal name,Barqos ("son of Qos"),[5] referring to the 'father' of a family or clan of perhaps Edomite/Idumaeannəṯīnīm or temple helpers returning from theBabylonian exile.[6][7] Outside the Bible, Qos is frequently invoked in names found on documents recovered from excavations inElephantine, where a mixed population of Arabs, Jews and Idumeans lived under the protection of a Persian-Mesopotamian garrison.
The word "Qos" is never used on its own in theTanakh, however it does unambiguously appear twice as an element in a personal name inEzra 2:53 andNehemiah 7:55 asBarqos, "son of Qos".[8] The nameQōs itself may meanbow.[9]
Qōs became identified withQuzah, "the archer" in the north Arabian pantheon, worshiped both as a mountain and a weather god. The similarity of the name would have permitted an assimilation of Qōs to the Arabian god of the rainbow,qaws quzaḥ.[10]
The worship of Qōs appears to originally have been located in the Ḥismā area of southern Jordan and north-western Arabia, where a mountain,Jabal al-Qaus, still bears that name.[6] He entered the Edomite pantheon as early as the 8th century B.C. M. Rose speculates that, prior to Qōs's advent, Edom may have worshipped Yahweh—early Egyptian records reference a place calledyhw in the land of theShasu[11]—and the former then overlaid the latter and assumed supremacy there when the Idumeans lost their autonomy under Persian rule, perhaps compensating for the destruction of national independence, a mechanism similar to that of the strengthening of Yahweh worship after the fall of the Jewish kingdom.[6] Qōs is described as a "King", is associated with light, and defined as "mighty". His works are described as ones where he "adorns, avenges, blesses, chooses(?) gives".[7]

Costobarus I, whose name means "Qōs is mighty",[10] was a native Idumean descended from a priestly family attached to this cult.[12] AfterHerod had placed him in command over (στρατηγὀς) Idumea, Costobarus, supported byCleopatra, eventually tried to seize the kingdom from Herod's Judea. In order to garner local support for his defection, he revived the old cult of Qōs, perhaps to get Idumea's rural population, still attached to its traditional gods, to back him.[13] The name recurs in theNabataean language in an inscription atKhirbet et-Tannur, where he is syncretized with the deityDushara, who is represented flanked by bulls, seated on a throne while wielding in his left hand a multi-pronged thunderbolt, suggestive of a function as a weather god.[10] He is also on an altar in IdumeanMamre.[13]
The deity's name was used as thetheophoric element in many Idumean names,[14] including the names of the Edomite kingsQōs-malaku, a tributary ofTiglath-Pileser III andQōs-gabar[15] a tributary ofEsarhaddon.[16]
Unlike the chief god of theAmmonites (Milcom) and theMoabites (Chemosh), theTanakh refrains from explicitly naming the Edomite Qōs.[6][17] The omission may be explained, according to some scholars, by assuming there were close similarities between Yahweh and Qōs, which would have made rejection of the latter difficult.[9] Other scholars have suggested that the tensions between Judeans and Edomites during theSecond Temple period may lie behind the omission of Qōs in the Bible.[18]
A poetic refrain in Judges in the Hebrew Bible states that Yahweh embarked fromSe'ir in the region ofEdom.[6][19] Recently,the view has been advanced that Yahweh was originally aKenite god whose cult spread north ofMidian to the Israelites.[20] According to this approach, Qōs might possibly have been a title for Yahweh, rather than a name.[21] A further point connecting Yahweh with Qōs, aside from their common origin in that territory, is that the Edomite cult of the latter shared characteristics of the former. Thus, we find thatDoeg the Edomite has no problem in worshiping Yahweh, he is shown to be at home in Jewish sanctuaries. Circumcision, an essential Jewish rite, was practiced in Edom.[2] Additionally, supplication of Yahweh is not uncommon where mentions of Qos are lacking: a pottery sherd from the late 9th/early 8th centuries BCE atKuntillet Ajrud blesses its recipient by "Yahweh ofTeman", which some have taken as implying that, at least from an Israelite perspective, Qos and Yahweh were considered identical, though it by no means necessarily proves it. On the other hand, there are some discrepancies which make a direct association between the two difficult. The identification of names in the Egyptian list ofShasu clans inSe'ir creates a continuity problem, since Qos names only emerge some 500 years later.[22] Oded Balaban andErnst Axel Knauf have claimed that certain names found onRamesside topographical lists are theophoric and contain references to Qos, which if true would put the deity's earliest attestation more than 600 years before Yahweh's.[23]