'It is the Lord' in the Bible

Then Samuel gave him an account of everything, keeping nothing back. And he said, It is the Lord; let him do what seems good to him.

Let my lord the king give ear now to the words of his servant. If it is the Lord who is moving you against me, let him take an offering: but if it is the children of men, may they be cursed before the Lord, for driving me out today and keeping me from my place in the heritage of the Lord, saying, Go, be the servant of other gods.