Genesis 26:31-33

31And 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.

32On that same day, Isaac’s servants came and told him about the well they had dug. “We have found water!” they told him. 33So he called it Shibah,1 and to this day the name of the city is Beersheba.2