What does it mean to collect debts from others and get the salty mountains and rivers to change the ground? Please tell me what it means.

It means that if you ask him for a big watermelon, you should get a big watermelon, but even if you succeed, you will only get a sesame seed. That is to say, the gain outweighs the loss! Suggestion: If the amount is not large, consider investing, or write down an IOU, and wait until he becomes a rich man before asking for it! As long as the IOU is there, it doesn't matter.