Genesis 21:28

26Abimelech said, “I don’t know who has done this thing. You didn’t tell me, and I didn’t hear of it until today.”

27Abraham took sheep and cattle, and gave them to Abimelech. Those two made a covenant.

28Abraham set seven ewe lambs of the flock by themselves.

29Abimelech said to Abraham, “What do these seven ewe lambs, which you have set by themselves, mean?”

30He said, “You shall take these seven ewe lambs from my hand, that it may be a witness to me, that I have dug this well.”