Most of your translation say in verse 7 “W…HO” are you, O great mountain? The nasb correctly translates this as “What” are you…This is not referring to a mountain of “fear, hindrance, lack, etc.” This in that day was referring to the “temple”, the place the Jews put utmost attention to. It was also speaking of the fulfillment of the temple being destroyed in 70Ad also prophesied by Jesus, the true cornerstone in Luke 19:41-44:
And when He approached, He saw the city and wept over it, saying, “If you had known in this day, even you, the things which make for peace! But now they have been hidden from you eyes. For the days shall come upon you when your enemies will throw up a bank (wall or mound for siege purposes) before you, and surround you and hem you in on every side, and will level you to the ground and your children within you, and they will not leave in you one stone upon another, because you did not recognize the day of your visitation.”
Many are making the same mistake today! Many go to the “temple of the Lord”, but do we know the “Lord of the temple (house)!” Many are also looking for another physical temple to be built and hopefully finally bring them peace. But the Prince of Peace is looking for “sons of peace” who are letting Him build His temple and peace in them. He (Jesus) is the cornerstone to this foundation and peace, and of the increase of His government and peace there shall be no end.
So, again, today, “It is not by might, nor by power, but by My Spirit”, says the Lord of Hosts. The House of the LORD has been brought to “level ground” once again, but He will raise up the headstone with shouts of “GRACE, GRACE, to it!” Let us echo this shout of FAVOR, FAVOR and BLESSING, BLESSING, for the LORD is building His House, with grace and truth, and with grace and glory! Ps. 84:11; Eph. 2:20-22)