Daniel 7:15-21
Daniel 7:15
I Daniel was grieved in my spirit in the midst of my body, and the visions of my head troubled me.
After Daniel had the seen the vision and the beasts associated with that vision, he now became very grieved because he saw the destruction that those beasts would bring on the world and especially on the saints of God until the last day.  The word “grieved” is an Aramaic word which is only used once in the Old Testament.  It is a verb which is in the Ithpael stem which makes it an intensive reflexive.  It expresses extreme emotion within Daniel in response to the visions.  It can be understood as being dismayed or being distressed.  Daniel also became very troubled because of the visions he was receiving.  The word “troubled” carries with it the meaning of to be “greatly troubled in an immediate time frame.”  In other words, as soon as he saw the visions, he became very troubled at them.
Daniel 7:16
I came near unto one of them that stood by, and asked him the truth of all this. So he told me, and made me know the interpretation of the things.
Daniel was no doubt still in the vision which means he was not awake.  He was still seeing the visions and in the visions he had walked over to one of the attending angels and asked him if he would give him the truth of these visions.  Daniel was given the understanding of the visions, so he knew what was to happen.  The one who spoke with him was the angel Gabriel.  Daniel 9:21 (KJV)  Yea, whiles I was speaking in prayer, even the man Gabriel, whom I had seen in the vision at the beginning, being caused to fly swiftly, touched me about the time of the evening oblation. 
Daniel 7:17
These great beasts, which are four, are four kings, which shall arise out of the earth.
Thee great beasts are the four kingdoms we have seen but here they are represented by their kings.  When we come to the fourth kingdom, there will be many different emperors who will rule for hundreds of years.  We saw the fourth kingdom as Rome.  Daniel is told about the 4 kingdoms.  The first one is Babylon which is already established because he is part of the ruling body of the province of Babylon.  Then succeeding Babylon will be the Medes and Persians.  The succeeding the Medes and the Persians will be Greece, and succeeding Greece will be Rome.  The Scripture states these kingdoms will arise out of the earth, that is, they will be earthly kingdoms and not heavenly kingdoms.  They will be of a temporary nature.
Daniel 7:18
But the saints of the most High shall take the kingdom, and possess the kingdom for ever, even for ever and ever.
Here Daniel has a vision of what is going to take place after all the earthly kingdoms of this world have been burned up and the world made anew.  Notice the word “kingdom” is used twice and both times they are singular which means only one kingdom and that will be the kingdom of God which will include the new heavens and the new earth.  These will not be like the kingdoms which arose out of the earth but will be divine in nature and will last for eternity.  Only the saints of God, those who are born again in Christ, will be allowed to enter the Kingdom of God eternally.
Daniel 7:19
Then I would know the truth of the fourth beast, which was diverse from all the others, exceeding dreadful, whose teeth were of iron, and his nails of brass; which devoured, brake in pieces, and stamped the residue with his feet;
In contrast to the saints taking the kingdom of God forever as their domicile, Daniel now wants to know the truth or meaning of the fourth beast or kingdom.  This fourth kingdom was diverse or altered from the other three kingdoms and he wanted to know why this kingdom was so fierce.  Teeth are used to chew and people must be careful if they chew something hard because they could break a tooth but the teeth of iron which is described here shows that whatever this beast chews up will be swallowed in little pieces no matter how hard the material was that is chewed, the teeth of iron will devour it.  Daniel introduces a new description here and that is the “nails of brass.”  It symbolizes that whatever it holds in its claws, it will never let go.  It has the ability to hold what was conquered.  Rome broke up kingdoms and brought them into subjection as vassal states.  All the rest were stamped, that is, crushed, the remainder of any people who resisted them which is represented by the feet crushing whatever vassal province is under its foot.
Daniel 7:20
And of the ten horns that were in his head, and of the other which came up, and before whom three fell; even of that horn that had eyes, and a mouth that spake very great things, whose look was more stout than his fellows.
Daniel was also seeking to know the meaning of the ten horns which emanated from the head of the fourth beast.  He was also puzzled about the horn which came up and displaced three other little horns.  That horn which had eyes and a mouth which spake many blasphemies was also a puzzle to Daniel and was hoping to get the interpretation of it.  He was also puzzled about this fourth kingdom being more stout or greater than the other three.  Daniel was part of the kingdom of Babylon and saw how great it was so it naturally puzzled him as to what kingdom could crop up that would exceed the size of Babylon.
Daniel 7:21
I beheld, and the same horn made war with the saints, and prevailed against them;
The fourth kingdom was Rome and it made war with the saints and seemed to overcome them.  There were ten major Roman persecutions of the Christians.  It caused the church to go underground and it seemed that the church was going out of existence.  Now this war with the saints did not stop with the Roman Empire because Rome went into extinction in the 6th century A.D. but the war against the saints continues right down to today.  The little horn was the power behind Rome and it is the power behind every kingdom or country which persecutes the Christians.  In the book of Revelation, we have two scenarios which coincide with what Daniel was seeing in his visions.