Genesis 21:25

At that time, Abimelech and Phicol the captain of his army spoke to Abraham, saying, “God is with you in all that you do.

Now, therefore, swear to me here by God that you will not deal falsely with me, nor with my son, nor with my son’s son. But according to the kindness that I have done to you, you shall do to me, and to the land in which you have lived as a foreigner.”

Abraham said, “I will swear.”

Abimelech said, “I don’t know who has done this thing. You didn’t tell me, and I didn’t hear of it until today.”

Abraham took sheep and cattle, and gave them to Abimelech. Those two made a covenant.

Abraham set seven ewe lambs of the flock by themselves.