John Calvin Commentary Exodus 19:13

"no hand shall touch him, but he shall surely be stoned, or shot through; whether it be beast or man, he shall not live: when the trumpet soundeth long, they shall come up to the mount." — Exodus 19:13 (ASV)

There shall not a hand touch it.²¹⁵ Those who interpret the particle ב, be, as the adversative 'else' ignorantly pervert the meaning, as if Moses forbade them to touch the mountain with their hand under penalty of stoning.²¹⁶ Those also are far from the truth who think that the ordinance means that one person should not follow another, or that no one should extend a hand to help the transgressors.

Moses referred to something altogether different; for in order to make those who by rash advances would violate the limits placed by God even more detestable, He commanded them to be killed from a distance by stones or darts, as if whoever touched them, even with a finger, would contract pollution. It is, then, as if He commanded them to be avoided as accursed, to prevent them from infecting others by their contagion.

Therefore, there is an antithesis between different kinds of death: namely, striking with the sword or shooting through with darts, and striking with the hand. However, so that the people would not consider themselves rejected and, offended by the ignominy of their repulse, abandon their love and desire for the Law, He permitted their ascent conditionally: namely, when the sound of the trumpet had been prolonged or had finished sounding. Thus, there was no reason to complain about the limitation God had appointed for their safety.

²¹⁵ There shall not a hand touch him, (eum.) — Lat..

²¹⁶ Aben-Ezra sic exponit: Qui praescriptum terminum transierit in hunc nemo injiciat manus, nemo illum sequatur intra constitutos limites, sed projiciant ad eum lapides, aut feriant eum jaculis. S. M. — — W.