“Can the leopard change his spots?”
Can the Ethiopian change his skin, or the leopard his spots? Neither are you able to do good, you who are accustomed to doing evil. (Jeremiah 13:23 BSB)
What it sounds like today
A familiar saying about things that cannot change.
The cultural key
This is the source of the everyday English idiom 'a leopard can't change its spots,' and knowing its origin sharpens the point. Jeremiah is not making a comment about race or animals but about the power of habit. Skin and spots are simply fixed, no effort alters them, and that is the analogy: a nation 'accustomed to doing evil' has practiced sin so long that it has become as ingrained and unchangeable as those markings. They can no more choose to 'do good' by willpower than a leopard can rearrange its coat. The verse is a sober diagnosis of moral inability, that persistent sin hardens into a second nature no self-effort can reverse, which is precisely why Jeremiah elsewhere speaks of sin 'engraved' on the heart (17:1) and looks ahead to God writing a new covenant on the heart instead. The proverb is bleak realism about entrenched evil, not a throwaway saying.
Recovered meaning
'Can the leopard change his spots?' is a proverb (the source of the modern idiom) about ingrained habit: as skin and spots are unchangeable, a people long practiced in evil cannot simply choose to do good. Sin has hardened into their nature.