So that place was called Beersheba, because it was there that the two of them swore an oath.

Genesis 21:14
Early in the morning, Abraham got up, took bread and a skin of water, put them on Hagar's shoulders, and sent her away with the boy. She left and wandered in the Wilderness of Beersheba.

Genesis 21:32
After they had made the covenant at Beersheba, Abimelech and Phicol the commander of his army got up and returned to the land of the Philistines.

Genesis 26:31
And they got up early the next morning and swore an oath to each other. Then Isaac sent them on their way, and they left him in peace.

Genesis 26:33
So he called it Shibah, and to this day the name of the city is Beersheba.

Genesis 46:1
So Israel set out with all that he had, and when he came to Beersheba, he offered sacrifices to the God of his father Isaac.

Joshua 15:28
Hazar-shual, Beersheba, Biziothiah,

1 Kings 19:3
And Elijah was afraid and ran for his life. When he came to Beersheba in Judah, he left his servant there,

Amos 5:5
Do not seek Bethel or go to Gilgal; do not journey to Beersheba, for Gilgal will surely go into exile, and Bethel will come to nothing.

Why he called that place Beersheba; because there they swore both of them.