This chapter is a flashback: It occurs before the feast that Belshazzar hosts in Chapter 5. Why does it end up here? What was Daniel's thought process in setting up his book this way? May have to continue reading the rest of the Book of Daniel before answering that. I did find an interesting tidbit in Matthew Henry's Commentary:
"Belshazzar’s name here is, in the original, spelt differently from what it used to be; before it was Bel-she-azar—Bel is he that treasures up riches. But this is Bel-eshe-zar—Bel is on fire by the enemy."
Bel is the god of the Chaldeans, and if he was at first the holder of the treasury of the Temple, he is, approaching Chapter 5, the one who will soon die for misusing the vessels of God's treasury. The thought that I shared with my group was that we needed to go back and re-read Chapter 5--looking at Daniel, his character and his presentation in light of the fact that he has had this vision of Chapter 7 before he confronts Belshazzar. It would make sense for Daniel to change the spelling of his name in Chapter 7, given that he witnessed happened to Belshazzar (a fulfillment of 2 visions for which he received interpretation, in the sense of the nations involved).
Looking at his vision, Daniel beholds "the four winds of heaven" stirring up "the great sea." (7:2) We discovered that the sea is often used scripturally to refer to people. Note that it was four winds of heaven. Who rules in Heaven? Let us not forget, throughout this entire prophecy, that God knows all! From the sea come four beasts. Most conservative Biblical scholars believe that the beasts correlate with the materials of Nebuchadnezzar's dream statue--the rising of the earthly kingdoms of Babylon, Medo-Persia, Greece and Rome.
Before we go much further: Will you read other thoughts on this in other commentaries? Sure you will. Prophecy was generally received as a message to folks living in a certain period of time, with their language and their points of reference, etc. There is the possibility for more than one fulfillment. The more we look at prophecy as being a future fulfillment, the more likely we will have multiple interpretations. It doesn't mean prophecy isn't important to us, nor should we disregard its message as being for us, on some level--but, we all need to seek God's wisdom and discernment when it comes to what is being said TO US in OUR time.
"Whether those visions look as far forward as the end of time, or whether they were to have a speedy accomplishment, is hard to say, nor are the most judicious interpreters agreed concerning it."
If you compare the statue materials of Chapter 2 with the beasts of Chapter 7, most of those comparisons seem pretty clear if not more so with the description of the beasts. The iron/clay kingdom of Chapter 2 suddenly becomes graphically "dreadful, terrifying and extremely strong" (7:7) in Chapter 7. Daniel didn't seem to know what to make of it at the time he saw it, as he was "contemplating the horns" when another one arose while he was still taking in the vision. It shouldn't surprise us that he asks for divine interpretation.
Although Matthew Henry mentions the Roman empire as being the 4th kingdom, he also says that some scholars suggest it could be Syria.
"And herein that empire was diverse from those which went before, that none of the preceding powers compelled the Jews to renounce their religion, but the kings of Syria did, and used them barbarously."--Matthew Henry
[Remember what I just said about seeking God's wisdom. We can read commentary like this and think--Syria? Compelling believers to renounce their religion? ISIS? Contemplate, but seek His wisdom through prayer.]
After all the beasts appear, Daniel sees the thrones of heaven being established. The Ancient of Days (7:9)--the Eternal One, God the Father--takes His seat. That "consuming fire" (Heb. 12:29) is a stark contrast to the images of these creatures. It is He who will judge. [Know what Daniel's name means? "God is my judge."]
"And thus God deals with his church’s enemies; sometimes he breaks the teeth of them (Ps. 3:7), when he does not break the neck of them, crushes the persecution, but reprieves the persecutors, that they may have space to repent. And it is fit that God, in doing his own work, should take his own time and way."--Matthew Henry
Daniel also received a new look at "the stone" from Chapter 2. The prophet sees "one like a Son of Man" (7:13) coming to the Ancient of Days. A vision of Christ! "And to Him was given dominion, glory and a kingdom, that all the peoples, nations and men of every language might serve Him." AMEN! Is this a promise from prophecy that we can cling to with surety? Absolutely! Plenty of Scripture to support this! "His kingdom will be an everlasting kingdom, and all the dominions will serve and obey Him." (7:27)
Can't escape from Daniel's asking, quite pointedly, as to the "exact meaning" (7:19) of the fourth beast. Again, commentators are open to not only one possibility for this ruler who will "wear down the saints of the Highest One." (7:25) The Syrian empire, closer to Daniel's day than ours, brought forth a king named Antiochus Epiphanes, who did horrible things to the Jews; if the Roman empire, Julius Caesar might be the "little horn" rising; it could be the Turkish empire; and, what about the antichrist, whose appearance, per Revelation, is a significant mark of the end of the world as we know it? One? Some? All??
What may concern us is the thought that this ruler will "wear down the saints" (NASB); "oppress his holy people" (NIV); "will be cruel to God's chosen ones" (CEV); "persecute the followers of the High God" (The Message). God goes so far in His message as to say that the saints will be "given into his [the king's] hand for a time, times and half a time." That period (translating to 3-1/2 years) coincides with the latter half of antichrist's rule, until the return of Jesus. It is no wonder Daniel is alarmed and literally paled, not knowing when such a time might be at hand and how his people are involved.
But, Daniel's vision ends with the reminder that this most oppressive ruler's dominion will be taken away and his kingdom destroyed forever (7:26). But, the kingdom coming to the Highest One will be the kingdom that stands forever, a kingdom "given to the people of the saints of the Highest One."
"The design of Satan has been to wear out the saints of the Most High, that they may be no more in remembrance; but the attempt is vain, for while the world stands God will have a church in it."
When the earth "dissolves like snow, the sun forbear to shine," God will bring the Church home to Himself. And prophecies will cease! (I Corinthians 13:8)