Thomas Aquinas, on Heb 12:20

“For they did not endure that which was said: And if so much as a beast shall touch the mount, it shall be stoned.”

“701. – He mentions the reason why they excused themselves, namely, because they could not endure God's words; hence, they could not endure the order that was given: 'What is all flesh that it should hear the voice of the living God, who speaks out of the midst of the fire, as we have heard, and be able to live' (Dt. 5:26). For God's words are said to be unendurable either when they cannot be understood by the intellect or transcend the affections. 702. – Then he gives the threatened punishment, saying: And if even a beast shall touch the mountain, it shall be stoned: 'Everyone that touches the mount, dying he shall die. No hands shall touch him, but he shall be stoned to death, or be shot through with arrows. Whether it be beast or man, he shall not live' (Ex. 19:12). The Apostle, to heighten the terror, mentions here only the beasts which the Law commands to be killed, in order to show the gravity of sin. Yet mystically the mountain is the loftiness of the divine mysteries, and the beast is a man living bestially: 'Man, when he was in honor, did not understand: he is compared to senseless beasts, and is become like to them' (Ps. 48:13). This beast touches the mount in two ways: first, by blasphemy: 'They have set their mouth against heaven' (Ps. 72:9); 'Bring forth the blasphemer outside the camp…, and let all the people stone him' (Lev. 24:14); secondly, by obtruding himself into divine matters: 'He that is a searcher of majesty shall be overwhelmed by glory' (Pr. 25:27).”

Imported from an open dataset — not yet checked against the printed edition.