When Ezekiel was finally back among the captives, he felt a great bitterness. He calls it, "the heat of my spirit." The New King James margin has at this point, "the anger of my spirit."
This heated or angry bitterness equates to a kind of zeal. God's revelation is actually its basis because what went down into his stomach and revealed or opened up a great deal of truth to him was from God. It has given him a perspective that no one else has—a unique view on the world, on the way things should be, and on all the truth of God. It brings him sadness, a kind of mourning, because of the crooked way of humanity.
Remember that the angel went about looking for those who sighed and cried over the abominations of the earth (Ezekiel 9:3-4). That is a deep sadness, a grieving over what is going on—along with a realization of one's powerlessness to change it. The people who sigh and cry see so many people going the wrong way and making their lives a total waste, and they find themselves unable to make any sort of beneficial change for them.
This zeal also contains a kind of astonishment, as verse 15 attests. Ezekiel was astonished for an entire seven days—a whole week! Trying to figure out just what was going on, he was dumbfounded. Probably part of it was that he had been given this commission, and he was asking, "Why me, Lord?" But he was also astonished by the understanding that he had been given and at what God was doing.
Finally, there is his anger. Somebody like Ezekiel would be angry because nothing was being done. It is the flipside of his sadness. He was angry that his people would not repent. He was likely thinking, "Come on, people. Listen! If you would only listen to God, things would turn around for you."
So the prophet shows a zeal to help people to change, but also a sadness that they probably will not. He also exhibits a total amazement over the fact that God is actually going to work all this out.
What Ezekiel displays is a weird emotion, but it is understandable why all of its facets are brought down to the one word: bitterness. There is little, if any, happiness and joy involved. It is the kind of mood where we say today, with a shake of the head, "Man, this is bad." It is an emotion on the very edge of downright pessimism.
What it does, though, is drive the prophet to do his work—because he is the only one, it seems, who can do it. Truly, he is, because God has chosen him in particular to do it. He may have picked somebody else, but He had prepared this particular individual for the job. And given a dose of that bitterness, the prophet is glavanized to get the job done.
Richard T. Ritenbaugh
The Two Witnesses (Part 2)