Isaiah 22:14

And it was revealed … hosts Render with R.V. And Jehovah of hosts revealed himself in mine ears. The message comes to the prophet like an external voice, which he knows to be that of the Lord (cf. ch. Isaiah 5:9).

Surely The form is that of adjuration (cf. Isaiah 14:24).

purged from you Better; expiated for you. Cf. 1 Samuel 3:14. The threat neither implies that the sin could be expiated by the death of the sinner, nor means merely that guilt would lie on them as long as they lived; it is a definite intimation that the unexpiated sin will call down punishment, and the punishment will be death.