Daniel 2:31

In all events Scripture says, "You, O king, were looking, and behold, one image: Great was that image and its appearance was fearful. The head of the image was of pure gold, its hands and chest and its arms were silver, the stomach and thighs were bronze, its legs were iron, the feet were part iron, part clay. You were looking until you saw a stone, which was cut without hands and it struck the image at the iron and clay feet and crushed it completely. Then once for all, the clay, iron, bronze, silver and gold were ground and they became like chaff from the summer threshing floor. And the greatness of the wind carried them away and no place was found for them. And the stone which struck the image became a great mountain and it filled all the earth. This is the dream and we will tell its interpretation before the king. You, O king, are the king of kings, to whom the God of heaven has given a strong, mighty, and honorable kingdom in every place where the sons of men dwell, and he has given into your hand beasts of the field and birds of heaven and he has ordained you Lord of all. You are the head of gold. And after you another kingdom shall arise, which is lesser than you. And a third kingdom shall arise which is bronze, which shall rule over all the earth. And a fourth kingdom will be strong as iron. In the way which iron grinds and subdues all, in this way it will grind and subdue all. And because you saw the feet and the toes, part of which were iron, part of which were clay, the kingdom shall be divided, and in it there shall be from the nature of iron, in which manner, you saw iron mixed with clay. […]

And so since the blessed Daniel described the vision and was not silent about its interpretation, he left behind some questions for those who possess a keen mind, so that again what was spoken by Daniel may be explained by another. Yet it is necessary for the lovers of truth, to not merely read cursorily, but to seek to say the obscure and to understand what was spoken by the prophets. For Daniel sees a great image, and the head of this he likens to be as pure gold. Next, the shoulders and chest he describes as being silver. Then, the stomach and thighs are bronze. Next, the legs are iron. Likewise also the toes of the feet are clay and iron which has been mixed together. Then, a stone, which is cut from a mountain without hands, strikes the image and grinds it. And the same stone became a great mountain and filled all the earth. After saying these things concerning the image, he afterwards divides the image, in accordance with its sections, into kingdoms and he explains each part of the statue, proceeding to each part, saying that the gold is king Nebuchadnezzar himself, describing him to be the golden head of the image. Next, he names a second kingdom, implying that it is inferior, saying that it is silver. Next, a third which is bronze. Then, a fourth strong kingdom, which is iron. Next, the clay and iron, having been mixed together, exhibit the tips of the feet of the image. For I have begun from the head because it displays the gold. Next, the chest and arms and he names them silver. Then, the stomach and thighs, and he indicates them to be bronze. Next, he describes the legs, and he shows them to be iron. […]

And so how can we not consider the ancient things which were prophesied by Daniel in Babylon and are now still being fulfilled in the world? For the image which was portrayed according to that season, embraced the model of the kingdom of all the world. In which season the Babylonians then reigned, as being the golden head of the image. Then after them the Persians ruled for two hundred forty-five years as they are shown to be silver. After them the Greeks ruled, beginning from Alexander of Macedon, for three hundred years, as they are bronze. After them the Romans, who are the iron legs of the image, being strong as iron. Next the toes of the feet, so that in each place democracies are shown, which are destined to be and which are divided into the ten toes of the image, in which the iron will have been mixed with clay.

"Thou sawest," etc. Apollinaris on this: He looked, and behold, as it were, an image. For it did not appear to him as an actual object, presented to the view of an onlooker, but as an image or semblance. And while it contains in it many things together, that is in such a way that it is not really one, but manifold. For it comprised a summary of all kingdoms; and its exceeding splendour was on account of the glory of the kings, and its terrible appearance on account of their power. Eusebius Pumphili, and Hippolytus the most holy bishop of Rome, compare the dream of Nebuchadnezzar now in question with the vision of the prophet Daniel. Since these have given a different interpretation of this vision now before us in their expositions, I deemed it necessary to transcribe what is said by Eusebius of Caesarea, who bears the surname Pamphili, in the 15th book of his Gospel Demonstration; for he expounds the whole vision in these terms: "I think that this (i.e., the vision of Nebuchadnezzar) differs in nothing from the vision of the prophet. For as the prophet saw a great sea, so the king saw a great image. And again, as the prophet saw four beasts, which he interpreted as four kingdoms, so the king was given to understand four kingdoms under the gold, and silver, and brass, and iron. And again, as the prophet saw the division of the ten horns of the last beast, and three horns broken by one; so the king, in like manner, saw in the extremities of the image one part iron and another clay. And besides this, as the prophet, after the vision of the four kingdoms, saw the Son of man receive dominion, and power, and a kingdom; so also the king thought he saw a stone smite the whole image, and become a great mountain and fill the sea. And rightly so. […]

And it was fitting that the king, who prized the substances deemed precious among people, gold, and silver, and brass and iron, should identify these substances as the kingdoms that held sovereignty at different times in the life of humankind; but that the prophet should describe these same kingdoms under the likeness of beasts, in accordance with the manner of their rule. And again, the king—who was puffed up, so it appears, in his own conceit and prided himself on the power of his ancestors—is shown the vicissitude to which affairs are subject and the end destined for all the kingdoms of the earth. This is done in order to teach him humility and understand that there is nothing lasting among people but only that which is appointed the end of all things—the kingdom of God.