I know his wrath, saith the LORD; but it shall not be so; his lies shall not so effect it.
I know his wrath - Moab's "proud arrogancy" (Jeremiah 48:29), or "wrath" against my people, is not unknown to me.
But it shall not be so - the result shall not be so as he thinks: his lies shall not so effect what he aims at by them. Calvin translates, 'his lies are not right (i:e., his vauntings are vain, because God will not give them effect): they shall not do so,' as they project in their minds, for God will set at nought their plans.