A radish is a pit, but minor injuries can't go down the line of fire.
Seriously injured, don't go to the hospital. According to the query of a radish and a pit, it is concluded that a radish and a pit can't be slightly injured, and the next sentence is that you don't go to the hospital if you are seriously injured. These two sentences refer to the revolutionary spirit that the front-line soldiers are not afraid of suffering and death in order to destroy the enemy more.