Genesis 31:50-52

50If thou shalt afflict my daughters, and if thou shalt take wives beside my daughters, no man is with us; see, God is witness betwixt me and thee.

51And Laban said to Jacob, Behold this heap, and behold the pillar, which I have set betwixt me and thee.

52This heap be witness, and the 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 unto me, for harm.