Philo Judaeus De Cherubim 53

And one may wonder at the kind of narration which the Jewish lawgiver frequently employs in many instances, where he departs from the usual style. For after giving the history of those parents of the human race who were created out of the earth, he begins to relate the story of the first-born of human parents, concerning whom he says absolutely nothing, as if he had already frequently mentioned his name, and were not now bringing it forward for the first time. Accordingly, he simply says that "she brought forth Cain." What sort of being was he, O writer; and what have you ever said about him before of either great or small importance?