Genesis 26:26-33

26When Abimelech went to him from Gerar with Ahuzzath his adviser and aPhicol the commander of his army, 27Isaac said to them, “Why have you come to me, seeing that you hate me and bhave sent me away from you?” 28They said, “We see plainly that the Lord has been with you. So we said, let there be a sworn pact between us, between you and us, and let us make a covenant with you, 29that you will do us no harm, just as we have not touched you and have done to you nothing but good and have sent you away in peace. cYou are now the blessed of the Lord.” 30So he made them a feast, and they ate and drank. 31In the morning they rose early and dexchanged oaths. And Isaac sent them on their way, and they departed from him in peace. 32That same day Isaac’s servants came and told him about the well that they had dug and said to him, “We have found water.” 33He called it Shibah;
 Shibah sounds like the Hebrew for oath
therefore the name of the city is fBeersheba to this day.

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