Genesis 21:27-32

21:27 Abraham took some sheep and cattle and gave them to Abimelech. The two of them made a treaty. 21:28 Then Abraham set seven ewe lambs apart from the flock by themselves. 21:29 Abimelech asked Abraham, “What is the meaning of these seven ewe lambs that you have set apart?” 21:30 He replied, “You must take these seven ewe lambs from my hand as legal proof that I dug this well.” 21:31 That is why he named that place Beer Sheba, because the two of them swore an oath there.

21:32 So they made a treaty at Beer Sheba. Then Abimelech and Phicol, the commander of his army, returned to the land of the Philistines.