Genesis 24:3

24:3 so that I may make you solemnly promise by the Lord, the God of heaven and the God of the earth: You must not acquire a wife for my son from the daughters of the Canaanites, among whom I am living.

Genesis 24:8-9

24:8 But if the woman is not willing to come back with you, you will be free from this oath of mine. But you must not take my son back there!” 24:9 So the servant placed his hand under the thigh of his master Abraham and gave his solemn promise he would carry out his wishes.