The Torah states that "when the ram's horn sounds" the people may ascend Mount Sinai (Exodus 19:13). The Mekhilta reads this literally: when the shofar "draws out" its sound — when its long blast signals that the divine presence has departed — then and only then may the people approach the mountain. Before that signal, touching the mountain meant death.
Rabbi Yossi takes this detail and extracts a principle that reaches far beyond Sinai: "It is not a man's place that honors him, but he that honors his place." The mountain itself had no inherent holiness. It was an ordinary peak in the Sinai wilderness — no temple, no altar, no history of sacred events. What made it untouchable was the presence of the Shechinah (the divine presence) resting upon it.
As long as God's presence was on the mountain, "whoever touches the mountain shall be put to death." The penalty was absolute. No exceptions, no gradations. The mountain had become the most dangerous place on earth — not because of anything in its geology or geography, but because the Creator of the universe was there.
Once the Shechinah departed, the mountain reverted to its natural state. All were permitted to ascend it. The same rocks, the same soil, the same peak — but now utterly ordinary. The holiness had never belonged to the place. It belonged to the Presence.
Rabbi Yossi's principle applies to every sacred space in Jewish thought. The Temple in Jerusalem, the Tabernacle in the wilderness, the mountain at Sinai — none of these places were holy in themselves. They were honored by the One who chose to dwell there. Remove the Presence, and the holiness departs with it.