Genesis 24:2-4

And Abraham said to his servant, the oldest of his household, who had charge of all that he had, “Put your hand under my thigh, that I may make you swear by the LORD, the God of heaven and God of the earth, that you will not take a wife for my son from the daughters of the Canaanites, among whom I dwell, but will go to my country and to my kindred, and take a wife for my son Isaac.”