Isaiah 2:2-4 And it shall come to pass in the last days, that the mountain [the Kingdom] of the LORD'S house shall be established in the top of the mountains[the little kingdoms of man], and shall be exalted above the hills [the little kingdoms of man];  and all nations shall flow to it.  And many people shall go and say, Come ye, and let us go up to the mountain [the Kingdom] of the LORD, to the house of the God of Jacob; and he will teach us of his ways, and we will walk in his paths: for out of Zion shall go forth the law, and the word of the LORD from Jerusalem.  And he shall judge among the nations, and shall rebuke many people: and they shall beat their swords into plowshares, and their spears into pruninghooks: nation shall not lift up sword against nation, neither shall they learn war any more.

This is a kingdom word.  The mountain here is not speaking of a physical mountain but a spiritual kingdom, the culmination of all that God is proposing to the church that is built according to His pattern, the pattern of Scripture.  This same word is given in Micah 4:1-5.

This word speaks of the culmination of the ages when the Lord will come forth in power.  The Lord will put down all spiritual and earthly power and authority in this age and in the age that is to come.  He will come with ten thousand of His faithful saints to set up His Kingdom, and that Kingdom is an everlasting one.  The Lord, Himself, will rule as King of kings and Lord of lords.  Everything will be put under His feet.  We don't now see all things put under His feet, but that day is coming.  Praise the Lord!

This Kingdom is again mentioned in Philippians 2:10-11 and in Daniel 2-41-45.