In it’s original form, Keynesian theory is sometimes pejoratively called “hydraulic macroeconomics”. The reason is that the model envisioned, roughly, economic actions flowing through the circular flow of the economy like fluids.
In that context, we macroeconomists used to talk about leakages and injections. Leakages were to be avoided. These happened when economic activity was diverted out of the circular flow. Injections into the circular flow were to be encouraged. And the role of the financial system was to make sure that saving didn’t leak out of the economy, but instead was quickly injected back in somewhere.
It turns out that in India, they have a huge and unusual leakage. Indians buy gold and donate it to Hindu temples. Those temples mostly hoard the gold.
Now India is considering various policy proposals designed to inject all that gold back into the economy.
There’s a dissertation waiting to be written on this.