'Witness' in the Bible

But you say, For what reason? Because the Lord has been a witness between you and the wife of your early years, to whom you have been untrue, though she is your friend and the wife to whom you have given your word.

And I will come near to you for judging; I will quickly be a witness against the wonder-workers, against those who have been untrue in married life, against those who take false oaths; against those who keep back from the servant his payment, and who are hard on the widow and the child without a father, who do not give his rights to the man from a strange country, and have no fear of me, says the Lord of armies.