Genesis 31:50-52

50If thou shalt afflict my daughters, or if thou shalt take other wives besides my daughters, no man is with us; see, God is witness between me and thee. 51And Laban said to Jacob, Behold this heap, and behold this pillar, which I have cast between me and thee; 52This heap be witness, and this pillar be witness, that I will not pass over this heap to thee, and that thou shalt not pass over this heap and this pillar to me, for harm.