The water analogy is good. A single drop of water over and over will penetrate the rock. If we acceralate the process by pushing million drops of water on a high speed? I think people use high speed water to cut diamond and superalloy.
The water has the abililty to dissipate or disperse or change direction, if you do not like the word "yielding".
Other common analogy is soft as cotton, fishnet or soccer goal net.
People use cotton in couch, ,mattress, padding glove etc. There are consisted of many threads. They will disperse the focused weight/force over many directions or "yield". Once the weight or the force is dispersed or empty out. It is "stopped" or supported.
The caught fish will flip and flop in all directions. It will bounce off the flat surface and get back to the water. If you use a fishnet, it will disperse or yield in many directions and still hold together. The fish's flipping and flopping forces are empty out.
The same idea with the soccer goal net to "catch" or stop the soccer ball in all directions and forces.
In short, if we rotate our arms, or use circular movements to disperse linear force from punching arms?
if we use our arms, body and legs like a fishnet?
we still have a holding together force, some may call it Peng or other wise.
To be soft is to be able to yield or follow the same direction of incoming forces and redirect the direction of the force away from us.
Just some thoughts.