'Concubines' in the Bible

Under the influence of the wine, Belshazzar gave orders to bring in the gold and silver vessels that his predecessor Nebuchadnezzar had taken from the temple in Jerusalem, so that the king and his nobles, wives, and concubines could drink from them.

So they brought in the gold vessels that had been taken from the temple, the house of God in Jerusalem, and the king and his nobles, wives, and concubines drank from them.

Instead, you have exalted yourself against the Lord of heaven. The vessels from His house were brought to you, and as you and your nobles, wives, and concubines drank wine from them, you praised the gods made of silver and gold, bronze, iron, wood, and stone, which do not see or hear or understand. But you have not glorified the God who holds your life-breath in His hand and who controls the whole course of your life.