The Viscosity of a liquid is the “thickness”, or how slowly it flows. Which layer of Earth do you think this is coming from?

Viscosity is the measure of resistance of a fluid to flow. A fluid that is highly viscous has a high resistance (like having more friction) and flows slower than a low-viscosity fluid. To think of viscosity in everyday terms, the easier a fluid moves, the lower the viscosity.
So it’ll come to the inner core/outer core.

Answer-ide.