So he named it Shibah; that is why the name of the city has been Beer Sheba to this day.
Referenced Verses
Gen 21:31 : 31 That is why he named that place Beer Sheba, because the two of them swore an oath there.
Gen 26:28 : 28 They replied,“We could plainly see that the LORD is with you. So we decided there should be a pact between us– between us and you. Allow us to make a treaty with you