There is only one place God has ever commanded a temple be built. Remember where that was?
Hint: It was not Gerizim.
Micah knows God is serious about this:
“The LORD is coming from his holy place; he will come down and walk on the tops of the mountains. Then the mountains will melt under him like wax in a fire; they will pour down into the valleys like water pouring down a hill. All this will happen because the people of Israel have sinned and rebelled against God.”
The correct answer is הַר הַבַּיִת