"Can the Ethiopian change his skin, or the leopard its spots? Then may you also do good, who are accustomed to doing evil."
The verse suggests that just as it is impossible for an Ethiopian (a person with dark skin) to change their skin color, or for a leopard to change its distinctive spotted coat, so too is it difficult for people who are habituated to doing evil to suddenly become good. The verse implies that certain habits or traits are deeply ingrained and difficult to alter.
Over time, the phrase "The leopard cannot change its spots" became a popular proverb used to express the idea that people cannot easily change their fundamental nature or ingrained characteristics. It's often used as a cautionary reminder that people should not expect significant transformations in others' behaviors or personalities, especially if those behaviors are negative or harmful. However, it's important to note that this proverb does not suggest that change is entirely impossible, but rather emphasizes the challenges and difficulties involved.