Genesis 21:31-33 World English Bible (WEB)
31 Therefore he called that place Beersheba,[a] because they both swore there. 32 So they made a covenant at Beersheba. Abimelech rose up with Phicol, the captain of his army, and they returned into the land of the Philistines. 33 Abraham planted a tamarisk tree in Beersheba, and called there on the name of Yahweh, the Everlasting God.