Genesis 31:50-52

50If you afflict my daughters, or if you take other wives besides my daughters, although no man is with us—see, God is witness between you and me!”

51Then Laban said to Jacob, “Here is this heap and here is this pillar, which I have placed between you and me.

52This heap is a witness, and this pillar is a witness, that I will not pass beyond this heap to you, and you will not pass beyond this heap and this pillar to me, for harm.