Chapter 10 Angelic Warfare.
In this remarkable chapter the veil of the other world is partly lifted. Daniel had seen the rise and fall of empires, but now he was to learn a little of the supernatural activity that lay behind such historical events. He was to learn of battles in the spiritual realm of which previously he had been unaware. Jacob had experienced such a glimpse into the other world at Bethel in Genesis 28:12; Genesis 28:17; Elisha was very much aware of it and prays that his servant too may have a glimpse of it (2 Kings 6:17, compare Daniel 2:11-12); Ezekiel saw it in the heavenly temple which descended on the unknown high mountain (Ezekiel 40:2) where he was able to examine it in depth; now Daniel is to have further revelation of that invisible world, brief but emphatic. It will then be followed by an outline of history leading up to the end of time.
But a central theme of the chapter is the physical effects it had on Daniel. Having to do with the spiritual realm in this way was physically and emotionally exhausting. This is emphasised again and again. He was overwhelmed by what he saw and experienced.