Genesis 21:31-33
31 Therefore that place was called Beer-sheba(a)(A) because it was there that the two of them swore an oath.
32 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.
33 Abraham planted a tamarisk tree in Beer-sheba, and there he called on the name of Yahweh, the Everlasting God.(B)
Footnotes:
a.
Genesis 21:31: Well of the Oath, or Seven Wells