Some say that this applies to some human king from the past. Yet, how many human kings are addressed as a “covering cherub” who was in “the midst of the fiery stones” and walked within “the mountain [nation] of God”? This angelic being is to be destroyed, and as the prophecy specifically states, it will be destruction by fire.
The Hebrew term translated “destroyed” is abad (Strong's #6). Vine's Complete Expository Dictionary of Old and New Testament Words states, “Basically, abad represents the disappearance of someone or something. In its strongest sense the word means 'to die or to cease to exist.'” In Ezekiel 28:18, God prophesies that He will turn the cherub Satan “to ashes upon the earth,” which certainly implies complete destruction.
A few other Old Testament verses will show this sense. Numbers 16:33 reads, “So they and all those with them went down alive into the pit; the earth closed over them, and they perished [abad] from among the assembly.” They were buried alive and disappeared. Deuteronomy 4:26 adds, forecasting Israel's demise as a nation, “I call heaven and earth to witness against you this day, that you will soon utterly perish [abad] from the land which you cross over the Jordan to possess; you will not prolong your days in it, but will be utterly destroyed.”
John W. Ritenbaugh
Do Angels Live Forever?