The age of the Gentiles began with Nebuchadnezzar, who was typified by the golden head in the great image. After him came Persia and Media, signified by the silver shoulders. Persia is today's Iran. Those two nations worked together as two shoulders. Because their authority was not as high as that of Nebuchadnezzar, they were signified by silver. Following these two empires was the empire of Greece, signified by the brass belly. Alexander crossed the Mediterranean Sea and defeated Persia and Media. After Greece came the Roman Empire, signified by the two legs. According to history the Roman Empire was divided into the western part and the eastern part. Thus, the two parts are the two legs. While the dignity of the Roman Empire did not compare with the others who were signified by the gold, silver, and brass, it was very strong as signified by the iron. Iron in the Bible signifies strength and power (Rev. 2:27; 12:5; 19:15; Psa. 2:9).
Both Daniel and Revelation tell us that after the Roman Empire there will be ten nations, signified in Revelation by the ten horns (Rev. 13 and 17). In those two chapters the ten horns signify the ten nations under the rule of the Antichrist. These ten nations are also the ten toes. Daniel 2 says that the stone will fall upon the image, that is, upon the Gentile powers. The Lord Jesus will smite the image. By falling upon the ten toes, the Lord Jesus will smite the entirety of the Gentile power. Christ is the stone who will smite the Gentile nations. What Daniel spoke corresponds to the Lord Jesus' words concerning the stone which the builders rejected in Matthew 21:44: "But on whomever it falls, it shall scatter him as chaff."
After the Lord smites the entire image, representing the whole Gentile world, the stone will become a great mountain which will fill the whole earth. This means that Christ as a stone will become the kingdom. A mountain in the Bible signifies a kingdom. The Lord Jesus will become the kingdom filling the whole earth. This word is fulfilled in Revelation 11:15: "The kingdom of the world has become the kingdom of our Lord and of His Christ, and He shall reign forever and ever." After the Lord Jesus terminates the Gentile dispensation, the whole earth will be filled with His kingdom. His kingdom is just the enlargement of Himself. The stone becomes the mountain. This means that Christ becomes the kingdom. The kingdom of the heavens is simply the enlargement of Christ. The Lord Jesus Himself is the King; when He gets into all of us, He becomes the kingdom. Thus, the stone becomes the mountain; Christ becomes the kingdom. While there are many other verses in the Old Testament concerning this matter, these are the representative verses.