Genesis 24:2-9

2Abraham said to his servant, the elder of his household who managed all he owned, “Place your hand under my thigh,

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

4but will go to my land and my family to take a wife for my son Isaac.”

5The servant said to him, “Suppose the woman is unwilling to follow me to this land? Should I have your son go back to the land you came from?”

6Abraham answered him, “Make sure that you don’t take my son back there.

7The Lord, the God of heaven, who took me from my father’s house and from my native land, who spoke to me and swore to me, ‘I will give this land to your offspring’  — he will send his angel before you, and you can take a wife for my son from there.

8If the woman is unwilling to follow you, then you are free from this oath to me, but don’t let my son go back there.”

9So the servant placed his hand under his master Abraham’s thigh and swore an oath to him concerning this matter.