'Concubines' in the Bible

David took him more concubines and wives out of Jerusalem, after he was come from Hebron; and there were yet sons and daughters born to David.

The king went forth, and all his household after him. The king left ten women, who were concubines, to keep the house.

Ahithophel said to Absalom, "Go in to your father's concubines, that he has left to keep the house. Then all Israel will hear that you are abhorred by your father. Then the hands of all who are with you will be strong."

So they spread Absalom a tent on the top of the house; and Absalom went in to his father's concubines in the sight of all Israel.

Joab came into the house to the king, and said, "You have shamed this day the faces of all your servants, who this day have saved your life, and the lives of your sons and of your daughters, and the lives of your wives, and the lives of your concubines;

David came to his house at Jerusalem; and the king took the ten women his concubines, whom he had left to keep the house, and put them in custody, and provided them with sustenance, but didn't go in to them. So they were shut up to the day of their death, living in widowhood.