Isaiah 2 and Exodus match on the following themes:
Exodus tells the story of Yahvah delivering the Israelites from bondage in Egypt. After crossing the Red Sea Yahvah brought Israel to Mt. Sinai.
The meeting between Yahvah and Israel was a long event. The rest of Exodus unfolds at the mountain as does Leviticus and the first ten chapters of Numbers. All together 58 chapters pass before Israel breaks camp and leaves the mountain.
Something special was happening in the meeting between Yahvah and Israel. In his first words to the Israelites since bringing them out of Egypt, Yahvah revealed that he was making Israel a nation of priests, a people that the other nations would watch.
The point of Israel's call into God's presence as a priest was to mediate for the other nations of the world. So even though something special was happening in Israel's encounter with Yahvah on the mountain, the scope of what was happening would eventually blow wide to all the nations of the world.
In Exodus 19, in preparation for the meeting between Yahvah and Israel, Yahvah specifically told Moses to tell the Israelites not to go up the mountain or even touch the mountain on the third day, the day when Yahvah would appear on the mountain.
Contrast Moses being told to stop anyone from going up the mountain with Isaiah 2:3 where many people say "Hey, let's go up the mountain of Yahvah." If Isaiah 2 is the same as Exodus, which it seems clear to me that it is, then maybe the people's idea to go up the mountain is to be avoided.
This may seem like an odd way to read Isaiah 2:3 if you've always thought running up the mountain to God must be a good thing, but consider that Hebrews says Yahvah calls people to be a priest, they do not take this honor on themselves (Hebrews 5:4). And consider that the context for this meeting at the mountain was the establishment of the nation of Israel as God's preist (Exodus 19). With that background we see why the corresponding passage in Isaiah 2 should be read as a bad idea when the people spontaneously decide to go up the mountain and see what's happening. One must be called up the mountain like Moses, Aaron, Joshua or the seventy elders later in the story.
After arriving at the mountain and being told their national call, Israel received the Ten Commandments and Law. Isaiah 2:3 references the law directly. The story is well known, beginning in Exodus 20:1 and running for chapters.
There's heavy symbolism used in Isaiah 2. Yahvah's "house" in verse two and the "house of God" in verse three are probably both a reference to the people of Israel. When Yahvah choose Israel out of all the nations of the world, he was essentially building himself a house, a people who would be in his presence. The Hebrew word for house just means "in" so the fuller sense of Yahvah's house is the place he was in. Yahvah had brought 603,550 Israelite families to the base of a mountain. (Numbers 2:32). Israel was swarming around Yahvah. Yahvah was "in" Israel. Israel was being established as Yahvah's house.
Israel also built a physical house for Yahvah. Nearly the entire second half of Exodus details the blueprints for the Tabernacle and its construction.
Later in Exodus, while Moses was on the mountain with Yahvah for forty days, the Israelites gave their gold to Aaron who built a golden calf. The Israelites then worshipped the golden calf and attributed their miraculous deliverance from Egypt to the golden calf.
The golden calf was eventually ground to powder and fed to the Israelites as drink.
The golden calf is the same as golden idols mentioned in Isaiah 2:20.
In Isaiah 2:21 the idol worshippers flee to caves to hide from Yahvah when he draws near. In Exodus someone else is hidden in the cleft of the rock, not because of his idolatry, or fear of being judged, but because who can look Yahvah in the face.
While Moses does not appear to have been an idol worshiper (he was on the mountain interceding for the golden calf idolatry) he was still placed in a cave when Yahvah passed by.