Genesis 21:14, 31-33

And Abraham rose up early in the morning, and took bread and a bottle of water, and gave it unto Hagar, putting it on her shoulder, and gave her the child, and sent her away: and she departed, and wandered in the wilderness of Beer-sheba.

Wherefore he called that place Beer-sheba; because there they sware both of them. So they made a covenant at Beer-sheba: and Abimelech rose up, and Phicol the captain of his host, and they returned into the land of the Philistines. And Abraham planted a tamarisk tree in Beer-sheba, and called there on the name of Jehovah, the Everlasting God.