That’s the Jewish belief:
From
JewishAnswers.org:
Moses’ Cushite Wife
Does it say somewhere in the Torah that Moses’ wife was black?
The answer to your question is found in Bamidbar (Numbers) 12:1, which tells us of the “Cushite” woman that Moses married. Cush is the area we call Ethiopia today, so someone from Cush would be black. Despite the fact that the Torah speaks of this Cushite wife, the fact that this wife is mentioned nowhere else in the Bible led many commentators, with Rashi at their head, to conclude that **this “Cushite” wife is none other than Moses’ wife Tzippora, who is called a Cushite euphemistically **for different reasons. Rashi’s take on it is that she was called a Cushite to make the point that the contrast of her incredible beauty to others was as obvious as the darkness of a Cushite. Other commentators, however, basing themselves on a work called “Moses’ chronicles” cited by a Midrash, explain that the Torah is referring to a woman Moses married (presumably after converting her to Monotheism) when he spent forty years in Cush after escaping Egypt the first time, before he ended up in Median with Tzipporah.
Thanks,
Raffy Davidovich
From the
Jewish Encyclopedia:
ZIPPORAH.
—Biblical Data:
Daughter of Jethro and wife of Moses. According to the Bible,Moses met the daughters of Jethro when they were being driven away from a well by shepherds; he assisted them, and was invited into the house of Jethro, who gave him Zipporah to be his wife (Ex. ii. 21). On his return to Egypt, Moses was accompanied by his wife, who saved him from great danger during their journey (ib. iv. 24-26). She appears to have returned with her children to her father’s house; for after the exodus from Egypt, Jethro brought Zipporah and her children out to Moses in the wilderness (ib. xviii. 2-5).
Zipporah is mentioned only once more in the Bible; namely, in Numbers xii. 1, where she is referred to as “the Ethiopian woman,” for having married whom Moses is upbraided by Miriam and Aaron.
—In Rabbinical Literature:
Zipporah is mentioned by the Rabbis alternately with praise and with blame. Her name (= “bird”) is explained as having been given her because, when questioned by her father as to the man who had rescued her, she flew out of the house like a bird and returned with Moses (Yalḳ., Shim’oni, i. 169). R. Joshua was of the opinion that Zipporah and Moses were always estranged, and that the latter did not love his wife (ib. 268).
The name “Cushite” was given to her, it is said, because she was distinguished from other women by her beauty, even as the Ethiopians differed from other people in their complexions.
The circumstance that she is twice referred to in one verse as “the Ethiopian” (Num. xii. 1) is explained as indicating that her actions were as distinctive as her beauty, and that she conducted herself no less royally while in her father’s house than when she became the wife of Moses (Yalḳ., Shim’oni, 1238; comp. also M. Ḳ. 16b; Yer. Sanh. x. 28d).