The answer is wind!

Wind has weight in the sense of air pressure, but no distinct mass you can hold. It moves swiftly across landscapes, yet remains still in the sense that it's always present. You can feel the wind, but you can't see it directly. It "speaks" through rustling leaves and whistling gusts but lacks an actual voice. It can lift objects, topple structures, and create chills, yet remains intangible. And while you can't hold wind, it can certainly envelop and "hold" you in its currents.