late 14c., "a message from a god, expressed by divine inspiration," from Old French oracle "temple, house of prayer; oracle" (12c.) and directly from Latin oraculum "divine announcement, oracle; place where oracles are given," from orare "pray, plead" (see orator), with material instrumental suffix -culo-. In antiquity, "the agency or medium of a god," also "the place where such divine utterances were given." This sense is attested in English from c.1400.
In the Old Testament used in every case, except 2 Sam. 16:23, to denote the most holy place in the temple (1 Kings 6:5, 19-23; 8:6). In 2 Sam. 16:23 it means the Word of God. A man inquired "at the oracle of God" by means of the Urim and Thummim in the breastplate on the high priest's ephod. In the New Testament it is used only in the plural, and always denotes the Word of God (Rom. 3:2; Heb. 5:12, etc.). The Scriptures are called "living oracles" (comp. Heb. 4:12) because of their quickening power (Acts 7:38).