The very thing /just the thing : If you say something is the very thing you think it's exactly what's needed.
Ex: Why not take garlic? It's the very thing for preventing colds.
Ex: Where did you get that old record player? It's the very thing for playing those jazz records I found in the attic.
Ex: A week's rest would be just the thing for her. ( Uma semana de descanso seria exatamente o que ela precisa)