This brings us into an almost rhapsodic passage with remarkable contrasts and comparisons. The writer is giving reasons why we must live holy lives, and admonish one another (verses 14-15).
Why is it said that Sinai could be touched when the people were forbidden to touch the mountain? The phrase, ‘mount that might be touched’ is simply intended to show that Sinai was a physical mountain. The verse does not mean they were allowed by God to touch it. It is described this way to contrast it with the heavenly Jerusalem, mentioned next, where the true Mount Sion resides, of which the earthly Sion was only a figure.