Genesis 24:2-3

Thomson(i) 2 And Abraham said to his servant, the oldest of his family and who was ruler over all that he had, Put thy hand under my thigh, 3 and let me cause thee to swear by the Lord the God of heaven and the God of earth, that thou wilt not take a wife for my son Isaak, of the daughters of the Chananites among whom I dwell;