The edge of a sword comes from sharpening, and the fragrance of plum blossoms comes from the bitter cold. The need to pinch the core of the pepper means that the pepper has to undergo the bad luck of pinching the core before it will produce more and full knots. It expresses that life will not be smooth sailing. Only by withstanding the wind and rain and overcoming setbacks can life be better. This sentence is consistent with the meaning that the edge of a sword emerges from sharpening and the fragrance of plum blossoms emerges from the bitter cold.