Genesis 26:28-31

28They replied, “We have clearly seen how the Lord has been with you. We think there should be an oath between two parties — between us and you. Let us make a covenant with you:

29You will not harm us, just as we have not harmed you but have done only what was good to you, sending you away in peace. You are now blessed by the Lord.”

30So he prepared a banquet for them, and they ate and drank.

31They got up early in the morning and swore an oath to each other. Isaac sent them on their way, and they left him in peace.