“For yee are not come vnto the mount that might be touched, and that burned with fire, nor vnto blacknesse, and darknes, and tempest,”
1611 King James Version (KJV)
12:18 For - A strong reason this why they ought the more to regard the whole exhortation drawn from the priesthood of Christ: because both salvation and vengeance are now nearer at hand. Ye are not come to the mountain that could be touched - That was of an earthy, material nature.
Heb 12:18 For ye are not come unto the mount. Ye should be diligent. Mount Sinai and the inauguration of the law are described. It was a mountain that might be touched, a mountain of earth, and that burned with fire. It burned on that occasion "with fire". See Ex 19:12-19.