According to the Hebrew Bible, the worship of this god, "the abomination of Moab," was introduced at Jerusalem by Solomon (1 Kings 11:7), but was abolished by Josiah (2 Kings 23:13). On the Moabite stone, Mesha (2 Kings 3:5) ascribed his victories over the king of Israel to this god, "And Chemosh drove him before my sight."
"The national god of the Moabites. He became angry with his people and permitted them to become the vassals of Israel; his anger passed, he commanded Mesha to fight against Israel, and Moabitish independence was reestablished (Moabite Stone, lines 5, 9, 14 et seq.). A king in the days of Sennacherib was called "Chemoshnadab" ("K. B." ii. 90 et seq. ; see Jehonadab). Chemosh was a god associated with the Semitic mother-goddess Ashtar, whose name he bears (Moabite Stone, line 17; compare Barton, "Semitic Origins," iv.). Peake wrongly holds that Ashtar-Chemosh was a deity distinct from Chemosh, while Moore and Bäthgen ("Beiträge zur Semitischen Religionsgeschichte," p. 14) regard "Ashtar" in this name as equivalent to "Astarte," who they believe was worshipped in the temple of Chemosh. "Ashtar" is more probably masculine here, as in South Arabia, and another name for Chemosh, the compound "Ashtar-Chemosh" being formed like "Yhwh-Elohim" or "Yhwh-Sebaoth." Whatever differences of conception may have attached to the god at different shrines, there is no adequate reason for doubting the substantial identity of the gods to whom these various names were applied. Hosea ix. 10 is proof that at some period (according to Wellhausen, at the time of the prophet himself) the impure cult of the Semitic goddess was practised at Baal-peor (compare Wellhausen, "Kleine Prophetell"; Nowack's Commentary; and G. A. Smith, "Twelve Prophets," ad loc.). Chemosh, therefore,was in general a deity of the same nature as Baal. On critical occasions a human sacrifice was considered necessary to secure his favor (compare II Kings iii. 27), and when deliverance came, a sanctuary might be built to him (Moabite Stone, line 3). An ancient poem, twice quoted in the Old Testament (Num. xxi. 27-30; Jer. xlviii. 45, 46), regards the Moabites as the children of Chemosh, and also calls them "the people of Chemosh."
The etymology of "Chemosh" is unknown. The name of the father of Mesba, Chemosh-melek ("Chemosh is Malik," or "Chemosh is king"; compare Moabite Stone, line 1), indicates the possibility that Chemosh and Malik (or Moloch) were one and the same deity. Judges xi. 24 has been thought by some to be a proof of this, since it speaks of Chemosh as the god of the Ammonites, while Moloch is elsewhere their god (compare I Kings xi. 7, 33). Several critics regard the statement in Judges as a mistake; but such an error was not unnatural. since both Chemosh and Moloch were developed, in different environments, from the same primitive divinity, and possessed many of the same epithets.
Solomon is said to have built a sanctuary to Chemosh on the Mount of Olives (I Kings xi. 7, 33), which was maintained till the reform of Josiah (II Kings xxiii. 13). This movement by Solomon was no doubt to some extent a political one, but it made the worship of Chemosh a part of the religious life of Israel for nearly 400 years".
However, according to II Kings xi. 7, evidence is given that Chemosh and Moloch were two different gods or perhaps two manifestations of the same god, at least to the peoples who worshiped them. Solomon had "high places" built for both gods at the same time and in the same location, "on the mountain which is East of Jerusalem." Both Chemosh and Molech may have had the same origins but if so, by Solomon's time they had been denominated into differing objects for different peoples, Chemosh for the Moabites and Moloch for the Ammonites. According to Genesis xix. 30-38, both the Moabites and the Ammonites were descended from the two sons of Lot (themselves half-brothers by his two daughters), Moab and Ben-ammi, which would corroborate the notion that they share a common origin.