In Parshat Behaalotcha, Bamidbar 12:1, we read: “Miriam and Aharon spoke about Moshe concerning the Cushite woman that he married, for, he married a Cushite woman.”
Rashi explains that everyone agreed to her beauty just as everyone agrees to the fact that the Cushites (Sudanese) have dark skin.
The Talmud, Moed Katan 16b states: Is Cushite her name? Her name is Tziporah! Rather, the word comes to teach us that just as a Cushite woman is different in the color of her skin, so Tziporah was unusual in the aspect of her deeds.
The Talmud brings another instance where we see the word Cush. King David used the word Cush in Tehillim 7:1 “A song of the shigayon by David which he sang to God concerning the matter of Cush ben Yemini.” The Gemara asks: Is Cush his name? But his name is Shaul! The Gemara explains: Cush is not his name but rather a characterization. Just as a Cushite is different in the color of his skin, so Shaul was unusual in the aspect of his deeds.
Rashi explains that Shaul was unique in being righteous while his generation was evil.
The Talmud quotes a similar idea from Amos 9:7 “Behold you are like the children of the Cushites to me, O children of Israel”. The Gemara asks: Is Cushites their name? But their name is Israel! Rather, the word teaches that just as a Cushite is different in the color of their skin, so are B’nai Yisrael different from all other nations in the aspect of their deeds.
We see from here that the Biblical word Cushite is interpreted by the Talmud to refer to someone who is different and unique.
However, beginning with the Civil Rights Movement in the 1960s, the use of the word Cushite in Modern Hebrew was no longer considered politically correct and is no longer acceptable in Israel today.