Chapters 8 – 11 are all a part of the same vision. In chapter eight, God lays the foundation as to why He is sending the punishment that is coming. Judah’s wholesale devotion to idolatry is “detestable” to Him. God does not regard it as trivial and He will punish them without pity. In chapter 8, Israel imagines God doesn’t care about them.
But things change in chapter 9. No longer is it that God doesn’t care. God, to them, has become irrelevant. And so, in this vision, God brings their punishment.
Note the movement of God in chapter 9. His presence ascends above the cherubim – always an indicator of the Lord’s presence. God takes the lead and the cherubim follow, and God moves to the door of the temple. By the end of chapter 11, the Lord will have moved totally out of Jerusalem.
The punishment Ezekiel sees in chapter 9 is not literal. It will take place, but it is not taking place in real time before Ezekiel’s eyes. What he sees is what is going to happen, and there will be no turning it back. The marking of the faithful is something we will see again in the book of Revelation. The notion is that God knows those are His, and those who are not.