Jeremiah 13:23 - Joseph Benson’s Commentary on the Old and New Testaments

Can the Ethiopian change his skin, &c. The word Cushi, here rendered Ethiopian, often signifies Arabian, in the Scriptures; Ethiopia being, by ancient writers, distinguished into Eastern (the same with Arabia) and Western Ethiopia. But here an inhabitant of the latter, that is, of Ethiopia properly so called, seems evidently to be meant, the people of that country, which lay south of Egypt, being much more remarkable than the Arabians for their black colour. It seems hardly necessary to observe to the reader, that Jeremiah does not intend to express here the absolute impossibility of a change taking place in the principles and practices of the ignorant and wicked. “To suppose this, would be to contradict the whole tenor of his writings, and to render insignificant and absurd all his invitations to repentance. Nay, it appears from the last verse of this chapter that he did not suppose the reformation even of this people to be an absolute impossibility. We are therefore to understand this as a proverbial expression, which, like many others in Scripture, is not to be taken in the strictness of the letter; the prophet designing only to express the extreme difficulty of a moral change in habitual sinners, and particularly in those presumptuous and obstinate sinners of Israel to whom his discourse is directed.” Dodd.