Genesis 21:31-33

31Therefore athat place was called Beersheba,
 Beersheba means well of seven or well of the oath
because there both of them swore an oath.
32So they made a covenant at Beersheba. Then Abimelech and Phicol the commander of his army rose up and returned to the land of the Philistines. 33Abraham planted a tamarisk tree in Beersheba and ccalled there on the name of the Lord, dthe Everlasting God.
Copyright information for ESV