Mt. Sinai set the new world's record for intimacy between God and humanity, and that intimacy was rightfully terrifying! Like the bush had, beforehand, now the whole mountain was burning with f-i-r-e and yet was not burned up. Like the flaming sword left to guard Eden, the burning boundary of Sinai was death to anyone who approached... to anyone except Moses, that is. Moses was not only allowed to come near, he came up, and he stayed for a while. One day, God even let him bring 73 others up to feast with the Lord.
This was God's new place to connect with his creatures. Sinai was God's new position on Earth.
At least for a time.
Now let's pause and consider Mt. Sinai/Horeb* before and after its famous occasions. Had the mountain been sacred before the bush burned? Did the mountain remain sacred while Moses went back to Egypt? Did God remain there, in some special way, even while God went with Moses to Pharaoh? Did Moses, Jethro or anyone else set up boundaries to keep that land untouched?
Was that plot of land made into a shrine, until the Israelites returned to Sinai (Horeb)? Or was Mt. Horeb/Sinai* merely normal dirt in the interim, until God led Moses back there with the Israelites, and then it became holy again? There are only two things to suppose about this. Either the land became holy forever once God declared it to be so, or the land became holy at whatever times God chose to dwell there.
It cannot be both ways. Either the land took on permanent holiness, because God had been there at one time, or else God's presentness made it holy, only during whatever times God chose to inhabit that place.
Let's consider both options.
To be continued...
(*) Note: if the majority opinion among scholars is incorrect about Horeb and Sinai being the same mountain, then Sinai was the *third* place God claimed, and thus Horeb (the second) would more definitely have been claimed for a temporary position. That's intriguing, but I've no plans to investigate further. Either way, the points made here should still apply.