Genesis 21:22-34

At that time Abimelech, accompanied by Phicol the commander of his army,  said to Abraham, “God is with you in everything you do.  Swear to me by God here and now, that you will not break an agreement with me or with my children and descendants. As I have been loyal to you, so you will be loyal to me and to the country where you are a resident alien.” And Abraham said, “I swear it.” But Abraham complained to Abimelech because of the well that Abimelech’s servants had seized.  Abimelech replied, “I don’t know who did this thing. You didn’t report anything to me, so I hadn’t heard about it until today.” Abraham took flocks and herds and gave them to Abimelech, and the two of them made a covenant.  Abraham separated seven ewe lambs from the flock. And Abimelech said to Abraham, “Why have you separated these seven ewe lambs? ” He replied, “You are to accept the seven ewe lambs from me so that this act  will serve as my witness that I dug this well.” Therefore that place was called Beer-sheba  , because it was there that the two of them swore an oath. After they had made a covenant at Beer-sheba, Abimelech and Phicol, the commander of his army, left and returned to the land of the Philistines. Abraham planted a tamarisk tree in Beer-sheba, and there he called on the name of the LORD, the Everlasting God.  And Abraham lived as an alien in the land of the Philistines for many days.