Genesis 21:25-31

And Abraham reproved Abimelech because of the well of water, which Abimelech’s servants had violently taken away. And Abimelech said, I know 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 they two made a covenant. And Abraham set seven ewe lambs of the flock by themselves. And Abimelech said unto Abraham, What mean these seven ewe lambs which thou hast set by themselves? And he said, These seven ewe lambs shalt thou take of my hand, that it may be a witness unto me, that I have digged this well. Wherefore he called that place Beer-sheba; because there they sware both of them.