Genesis 24:5-9

The servant answered, “But what if the woman refuses to leave home and come with me? Do I then take your son back to your home country?” Abraham said, “Oh no. Never. By no means are you to take my son back there. GOD, the God of Heaven, took me from the home of my father and from the country of my birth and spoke to me in solemn promise, ‘I’m giving this land to your descendants.’ This God will send his angel ahead of you to get a wife for my son. And if the woman won’t come, you are free from this oath you’ve sworn to me. But under no circumstances are you to take my son back there.” So the servant put his hand under the thigh of his master Abraham and gave his solemn oath.