The first inklings of clear anti-black sentiment appear appear in Talmudic Judaism, from around the 3rd century.
A Jewish version of Genesis in the Midrash Rabbah compilation of books of the Jewish Bible has Noah cursing Ham so that his seed “will be ugly and dark-skinned.” The message is reinforced in the Babylonian Talmud, where the Curse of Ham is explained as a result of Ham’s decision to break a ban on sex on the Ark, out of conviction that the first child born after the flood will inherit the world: after the deed, the Talmud explains, Ham’s skin turned black, a trait inherited by his descendants.