Genesis 21:29 (KJV)

And Abraham said, I will swear.

And Abraham reproved Abimelech because of a well of water, which Abimelech's servants had violently taken away.

And Abimelech said, I wot not who hath done this thing; neither didst thou tell me, neither yet heard I of it, but to day.

And Abraham took sheep and oxen, and gave them unto Abimelech; and both of them made a covenant.

And Abraham set seven ewe lambs of the flock by themselves.

And he said, For these seven ewe lambs shalt thou take of my hand, that they may be a witness unto me, that I have digged this well.

Wherefore he called that place Beersheba; because there they sware both of them.

Thus they made a covenant at Beersheba: then Abimelech rose up, and Phichol the chief captain of his host, and they returned into the land of the Philistines.

And Abraham planted a grove in Beersheba, and called there on the name of the LORD, the everlasting God.

And Abraham sojourned in the Philistines' land many days.