Ezekiel is addressed as the “son of man,” the “son of Adam” throughout his prophecy. This comes of course after having seen upon the heavenly throne “the likeness as the appearance of a man [Adam] upon it” (1:26). While there’s a good bit of allusion and symbolism in the vision of God that Ezekiel sees, the recurring reference to the “firmament” is striking since that isn’t a very common word, and apart from a couple of psalm appearances, this is the only other place it shows up with some frequency outside of Genesis 1.
Likewise, Ezekiel is being sent as the son of Adam, and he is instructed to not be afraid of the briers and thorns or the scorpions, allusions to the curse of sin, all of which seem (here) to be symbols of the words and looks of Israel. Yahweh says that they are a rebellious house, and Ezekiel should expect that sort of reception (2:6).
Of course, God spreads out his Word in the form of a scroll of a book before Ezekiel. It is a Word full of lamentations, mourning, and woe (2:10). And God says to Ezekiel, the son of Adam, “eat this roll” (3:1). And God says, “cause thy belly to eat, and fill thy bowels with this roll that I give thee.” Gotta love the KJV on this sort of passage. Of course Ezekiel obeys, and he says that as he ate the book it was like honey in his mouth (3:3).
This new Adam, like the old Adam, finds himself in the glory-presence of the Creator God, where the firmament is not a division between heaven and earth but the very point of union and communion between God and Man. And like the Adam of old, this new Adam is given instructions regarding food. Eat this book, he says.
Last, God points out that if Ezekiel were sent to a foreign land, to a people who spoke a different language than Ezekiel, they would stand a far great chance of understanding Ezekiel than the house of Israel (3:5-6). Their hard-heartedness is so far gone, their foreheads are so thick, and their faces so flinty that they cannot listen Ezekiel (3:7-9).
Sin does this sort of thing. Sin is not merely a bad idea; it makes people stupid. Sin makes people deaf and blind to truth, and when it comes and looks them in the eyes and talks to them, it sounds like a foreign tongue. And this becomes even more troubling when dealing with family and friends dear to us who have hardened their hearts; it’s like trying to communicate with an old relative who has Alzheimer’s. It’s the same person you’ve always known but something is terribly wrong and they don’t know who you are or what you’re talking about.