Exodus 19:13

Not an hand touch it. Or, “No hand shall touch him” (RSV). The one transgressing the divine command was not to be seized, for the one making the arrest would have to pass the “bounds” in order to do so. Instead, the transgressor was to be killed by stones thrown or arrows shot from within the “bounds.” The same was to be done to any beast that strayed into the restricted area, lest anyone be tempted to enter the restricted area to retrieve his stray animal. Everything was done to impress the Israelites with the awful majesty of God, and the spirit of solemnity that should fill one’s heart upon approaching the divine presence.

God is ever present (Ps. 139:1-12), but He veils His presence. Though He is with us we do not perceive Him (Job 23:8, 9). But when He does reveal His presence, all tremble before Him (Gen. 28:16, 17; Job 42:5, 6; Hab. 3:16). Weakness quakes before strength, littleness shrinks before greatness, finite man becomes insignificant in the presence of the Infinite. It is consciousness of sin that makes a man tremble before a holy God (Gen. 3:10). Corruption quails before incorruption, moral depravity before absolute purity.

They shall come up. The pronoun “they” cannot here refer to the people, for this would contradict the command of the previous verse. The people never did ascend the mount. But Moses, Aaron, Nadab, Abihu, and the 70 elders did (see Ex. 24:1, 2), and they are probably the ones here referred to.