When you push down on a bicycle pump, but do not let the air escape through the hose, what happens inside?

pushing on the bicycle pump with a force create a pressure inside and push the air towards the hose. since air can not escape through the hose, it turns back and apply the same pressure in the upward direction. this same pressure apply same pressure at the hands pushing in down direction. also since there is no way for the air to escape, there is no movement of the piston pushing the air the air inside.