Genesis 24:2-9

2Abraham said to his servant [Eliezer of Damascus], the oldest of his household, who had charge over all that Abraham owned, “Please, put your hand under my thigh [as is customary for affirming a solemn oath],

3and I will make you swear by the Lord, the God of heaven and the God of earth, that you will not take a wife for my son from the daughters of the Canaanites, among whom I live,

4but you will [instead] go to my [former] country (Mesopotamia) and to my relatives, and take a wife for my son Isaac [the heir of the covenant promise].”

5The servant said to him, “Suppose the woman will not be willing to follow me back to this country; should I take your son back to the country from which you came?”

6Abraham said to him, “See to it that you do not take my son back there!

7The Lord, the God of heaven, who took me from my father’s house, from the land of my family and my birth, who spoke to me and swore to me, saying, ‘To your descendants I will give this land’—He will send His angel before you [to guide you], and you will take a wife from there for my son [and bring her here].

8If the woman is not willing to follow you [to this land], then you will be free from this my oath and blameless; only you must never take my son back there.”

9So the servant put his hand under the thigh of Abraham his master, and swore to him concerning this matter.