Genesis 24:5-9

The servant asked, “But what if I can’t find a young woman who is willing to travel so far from home? Should I then take Isaac there to live among your relatives in the land you came from?” “No!” Abraham responded. “Be careful never to take my son there. For the LORD, the God of heaven, who took me from my father’s house and my native land, solemnly promised to give this land to my descendants. He will send his angel ahead of you, and he will see to it that you find a wife there for my son. If she is unwilling to come back with you, then you are free from this oath of mine. But under no circumstances are you to take my son there.” So the servant took an oath by putting his hand under the thigh of his master, Abraham. He swore to follow Abraham’s instructions.