'Swear by the Lord' in the Bible

and I will make you swear by the Lord, the God of heaven and the God of earth, that you will not take a wife for my son from the daughters of the Canaanites, among whom I live,

So now stand up, go out and speak kindly and encouragingly to your servants; for I swear by the Lord that if you do not go out, not a man will stay with you tonight. And this will be worse for you than all the evil that has come upon you from your youth until now.”

So the king sent word and called for Shimei and said to him, “Did I not make you swear by the Lord and solemnly warn you, saying, ‘Know for certain that on the day you leave [Jerusalem] and go anywhere, you shall surely die’? And you said to me, ‘The word (ruling) I have heard is good.’