Genesis 21:32 - 21:34
32 So they cut a covenant at Beersheba; and Abimelech and Phicol, the commander of his army, arose and returned to the land of the Philistines. 33 And Abraham planted a tamarisk tree at Beersheba, and there he called upon the name of Yahweh, the Everlasting God. 34 And Abraham sojourned in the land of the Philistines for many days.