Genesis 26:23-26:29
From there he went up to Beer-sheba. That night the Lord appeared to him and said, "I am the God of your father Abraham. Fear not, for I am with you, and I will bless you and increase your offspring for the sake of My servant Abraham." So he built an altar there and invoked the Lord by name. Isaac pitched his tent there and his servants started digging a well. And Abimelech came to him from Gerar, with Ahuzzath his councilor and Phicol chief of his troops.
Isaac said to them, "Why have you come to me, seeing that you have been hostile to me and have driven me away from you?" And they said, "We now see plainly that the Lord has been with you, and we thought: Let there be a sworn treaty between our two parties, between you and us. Let us make a pact with you that you will not do us harm, just as we have not molested you but have always dealt kindly with you and sent you away in peace. From now on, be you blessed of the Lord!"