(As Ørberg’s Sermones have words altered from the original, I decided to just read other texts made for beginners. If I am to read original authors, let me read their own words!)
In “Uterque [Cainus et Abel] obtulit dona Domino: Cainus quidem fructus terrae; Abel autem oves egregias“, that quidem does not seem to mean “too“ nor “yet“ nor any of the meanings of Lewis and Short. Now, I know Donatus called it “expletiva”; is it, then, just continuing thought, more or less like the Greek δέ? Or can it work like a “scilicet“, and the meaning would be “Both gave the Lord their offerings; namely, Cain gave the fruits of the earth, while Abel gave his best sheep“?