Genesis 24:2-4

And Abraham said to his chief servant, the manager of all his property, Come now, put your hand under my leg: And take an oath by the Lord, the God of heaven and the God of the earth, that you will not get a wife for my son Isaac from the daughters of the Canaanites among whom I am living; But that you will go into my country and to my relations and get a wife there for my son Isaac.