Source: Book lll (beginning) Contents of the Third Book of Diodorus (University of Chicago) 90-21 B.C.
From the source, “Now the Ethiopians, as historians relate, were the first of all men and the proofs of this statement, they say, are manifest. For that they did not come into their land as immigrants from abroad but were p91 natives of it and so justly bear the name of “autochthones”​1…They say also that the Egyptians are colonists sent out by the Ethiopians, Osiris having been the leader of the colony. 2 For, speaking generally, what is now Egypt, they maintain, was not land but sea when in the beginning the universe was being formed; afterwards, however, as the Nile during the times of its inundation carried down the mud from Ethiopia, land was gradually built up from the deposit. Also the statement that all the land of the Egyptians is alluvial silt deposited by the river receives the clearest proof, in their opinion, from what takes place at the outlets of the Nile; 3 for as each year new mud is continually gathered together at the mouths of the river, the sea is observed being thrust back by the deposited silt and the land receiving the increase. And the larger part of the customs of the Egyptians are, they hold, Ethiopian, the p95 colonists still preserving their ancient manners. 4 For instance, the belief that their kings are gods, the very special attention which they pay to their burials, and many other matters of a similar nature are Ethiopian practices, while the shapes of their statues and the forms of their letters are Ethiopian; 5 for of the two kinds of writing​5 which the Egyptians have, that which is known as “popular” (demotic) is learned by everyone, while that which is called “sacred”​6 is understood only by the priests of the Egyptians, who learn it from their fathers as one of the things which are not divulged, but among the Ethiopians everyone uses these forms of letters…With regard to the gods, the Ethiopians who dwell above Meroë entertain two opinions: they believe that some of them, such as the sun and the moon and the universe as a whole, have a nature which is eternal and imperishable, but others of them, they think, share a mortal nature and have come to receive immortal honours because of their virtue and the benefactions which they have bestowed upon all mankind; 2 for instance, they revere Isis and Pan, and also Heracles and Zeus, considering that p109 these deities in particular have been benefactors of the race of men. But a few of the Ethiopians do not believe in the existence of any gods at all;​15 consequently at the rising of the sun they utter imprecations against it as being most hostile to them, and flee to the marshes of those parts.”
Diodorus Siculus confirms the biological and cultural link shared amongst ancient Egyptians and Ethiopians. This source confirms that the ancient Egyptians considered their home to be in the African continent (geographically speaking, Ethiopia is below Egypt) which aligns with Ezekiel 29:14.
This source also confirms that an euhermistic view of pagan deities like Zeus is most appropriate because that is how many of the Ethiopians viewed them.
and then