Zechariah 1:8

It is quite clear that all the things shown to the prophet were tokens of certain realities, just as Joseph saw sheaves, sun, moon and stars, each of which carried a clue to some coming event, and the Pharaoh saw ears of corn and oxen, some fat and some skinny, and by these as well other events were signified from what was shown. In exactly the same way the prophet also sees these things by divine revelation, and each of the things shown him contained some sign or indication of a reality. Likewise blessed Peter also saw a cloth let down from heaven, full of various living creatures clean and unclean, and the vision contained a clue to some other things.

It is clear that those who were seen are invisible powers, "sent for service," according to the divine apostle, "for the sake of those who are due to inherit salvation." Their natures are not seen, however, being incorporeal: he who is Lord of them and of everyone else renders them discernible according to need in each case. The divine Scripture clearly teaches us this, giving a glimpse of their different forms: Daniel saw them in one fashion, Ezekiel in another fashion, and Isaiah and Micah in different forms. Not that they have many forms, being naturally incorporeal and spiritual: the Lord of all when need arises gives them a form for discernment. This he did also in the case of Zechariah: he reveals to him the angel who is a leader of the people; St. Michael was this angel.

[Daniel 7:5] "And behold another beast like a bear stood up on one side; and there were three rows in his mouth and in his teeth; and they said to him: 'Arise up and devour flesh in abundance.'" The second beast resembling a bear is the same as that of which we read in the vision of the statue (2:32): "His chest and arms were of silver." In the former case the comparison was based on the hardness of the metal, in this case on the ferocity of the bear. For the Persian kingdom followed a rigorous and frugal manner of life after the manner of the Spartans, and that too to such an extent that they used to use salt and nasturtium-cress in their relish. Let us consult the record of the childhood of Cyrus the Great (i.e., "The Education or Training" of Cyrus). And as for the fact that the bear is said to have "stood up on one side," the Hebrews interpret it by saying that the Persians never perpetrated any cruelty against Israel. Hence they are described in the Prophecy of Zechariah also as white horses (Zechariah 1:7-11). But as for the three rows or ranks that were in his mouth and between his teeth, one authority has interpreted this to mean that allusion was made to the fact that the Persian kingdom was divided up among three princes, just as we read in the sections dealing with Belshazzar and with Darius that there were three princes who were in charge of the one hundred and twenty satraps. But other commentators affirm that these were three kings of the Persians who were subsequent to Cyrus, and yet they fail to mention them by name. But we know that after Cyrus's reign of thirty years his son Cambyses ruled among the Persians, and his brothers the magi, and then Darius, in the second year of whose reign the rebuilding of the Temple was commenced at Jerusalem. The fifth king was Xerxes, the son of Darius; the sixth was Artabanus; the seventh, Artaxerxes who was surnamed Makrokheir, that is Longimanus ("Long-handed"); the eighth, Xerxes; the ninth, Sogdianus; the tenth, Darius surnamed Nothos ("Bastard"); the eleventh, the Artaxerxes called Mnemon, that is, "The Rememberer"; the twelfth, the other Artaxerxes, who himself received the surname of Ochus; the thirteenth, Arses, the son of Ochus; and the fourteenth, Darius the son of Arsamus, who was conquered by Alexander, the king of the Macedonians. How then can we say that these were three kings of the…