John Gill Commentary Genesis 31:52

"This 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." — Genesis 31:52 (ASV)

This heap [be] witness Agreeably to its name, which both he and Jacob gave unto it: and [this] pillar [be] witness : which was set up for the same purpose: that I will not pass over this heap to you, and that you shall not pass over this heap and this pillar unto me, for harm ; not that these were to be the boundaries of their respective countries; for neither of them at present were possessed of lands that reached hither, if of any at all; nor that it would be a breach of covenant to pass over or by those, from one country into another, but so as to do, or with an intent to do, hurt to each other.