, so are the children of Israel different in their conduct from all other nations.……May all the world become so! Amen
[The Gemara [Talmud] asks: Why is Saul referred to as Cush?] Was Cush his name? [The Gemara answers:] Just as a Cushite [an Ethiopian] stands out for his skin color, so did Saul stand out for his good deeds. In a similar vein we explain the verse, “Miriam and Aaron spoke against Moses regarding the Cushite woman he had married” (Numbers 12:1). Was her name Cushit? Wasn’t her name Zipporah? But just as a Cushite [Ethiopian] woman stands out for the color of her skin, so did Zipporah stand out for her kind deeds. Another example: It says, “And Eved-Melech the Cushite heard . . ” (Jeremiah 38:7).Was his name Cushi? Wasn’t his name Zedekiah? But just as a Cushite [Ethiopian] stands out for the color of his skin, so did Zedekiah stand out for his good deeds. Similarly, it says, “To Me, O children of Israel, you are just like the Cushites [Ethiopians], declared God” (Amos 9:7). Wasn’t their name children of Israel? But just as a Cushite [Ethiopian] is different with his skin, so are the children of Israel different in their conduct from all other nations.
Finkel, Avraham Yaakov. Ein Yaakov (pp. 324-325). Jason Aronson, Inc.. Kindle Editio