John Wesley on Exodus 19:12

Set bounds - Probably he drew a ditch round at the foot of the hill, which none were to pass upon pain of death. This was to intimate, 1st, That awful reverence which ought to possess the minds of all that worship God. 2dly, The distance which worshippers were kept at under that dispensation, which we ought to take notice of, that we may the more value our privilege under the gospel, having boldness to enter into the holiest by the blood of Jesus, Heb 10:19.