Genesis 21:27-30

27Then Abraham took a flock of sheep and cattle and gave them to Abimelech, and the two of them made a covenant.

28Abraham set seven young ewe-lambs apart from the flock of sheep by themselves.

29Abimelech said to Abraham, “What do these seven ewe-lambs that you’ve set by themselves mean?”

30He said, “You are to accept the seven ewe-lambs from my hand, so that they may be a witness for me that I dug this well.”