In the Old Testament used in every case, except 2 Samuel 16:23, to denote the most holy place in the temple (1 Kings 6:5,19-23; 8:6). In 2 Samuel 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 (Romans 3:2; Hebrews 5:12, etc.). The Scriptures are called "living oracles" (Compare Hebrews 4:12) because of their quickening power (Acts 7:38).
These dictionary topics are from M.G. Easton M.A., D.D., Illustrated Bible Dictionary, Third Edition, published by Thomas Nelson, 1897. Public Domain, copy freely.
Easton, Matthew George. "Entry for 'Oracle'". "Easton's Bible Dictionary".