Genesis 24:6

3 That I may make thee swear by the Lord, the God of heaven and earth, that thou take not a wife for my son, of the daughters of the Chanaanites, among whom I dwell:

4 But that thou go to my own country and kindred, and take a wife from thence for my son Isaac.

5 The servant answered: If the woman will not come with me into this land, must I bring thy son back again to the place from whence thou camest out?

6 And Abraham said: Beware thou never bring my son back again thither.

7 The Lord God of heaven, who took me out of my father's house, and out of my native country, who spoke to me, and swore to me, saying: To thy seed will I give this land: he will send his angel before thee, and thou shalt take from thence a wife for my son.

8 But if the woman will not follow thee, thou shalt not be bound by the oath: only bring not my son back thither again.

9 The servant, therefore, put his hand under the thigh of Abraham, his lord, and swore to him upon his word.