1. One man holds the gate, but ten thousand men cannot break it: The mountain is high and dangerous, and if one man holds the gate, even ten thousand men cannot break in. The terrain is described as very dangerous.
2. Three days to fish, two days to dry the net: a metaphor for lack of perseverance and frequent interruptions.
3.
Mountains and rivers are easy to change, but nature is difficult to change: The change of human nature is more difficult than the changes of mountains and rivers. It refers to a habit that is hard to change.