In plain words
The poet, to the people of the world: You raise cruelty as your wall and rampart, and take on nothing but poverty for the life to come. You cannot know the time when this crumbling mansion, this outer wall [the body], will fall to the ground. Doing no servant’s work for Araṅgaṉ, who stands with righteousness as his wall, you adorn the outer wall, and lie there for the birds to peck at.