Genesis 21:31

31Therefore athat place was called Beersheba,
 Beersheba means well of seven or well of the oath
because there both of them swore an oath.

Genesis 26:33

33He called it Shibah;
 Shibah sounds like the Hebrew for oath
therefore the name of the city is dBeersheba to this day.

Judges 20:1

Israel’s War with the Tribe of Benjamin

1Then eall the people of Israel came out, ffrom Dan to Beersheba, including the land of Gilead, and the congregation assembled as one man to the Lord at gMizpah.
Copyright information for ESV