Et vidit Deus lucem quod esset bona: et divisit lucem a tenebris. Appellavitque lucem Diem, et tenebras Noctem: factumque est vespere et mane, dies unus.
And God saw the light that it was good: and he divided light away from darkness. And he named the light Day, and the darkness Night: and made were evening and morning, day one.
Just as “lucem” comes from “lux”, you’ll guess that “tenebris” comes from “tenebrae.” It takes that different form because of the preposition “a”.
If you want to carry on with the Bible, the Latin text and many different translations are easily found online. It’s a great resource for a student. The grammar is a lot simpler than most Latin texts, and the occasionally repetitive style really hammers home the vocabulary. It’s hard to forget that genuit means “he begat” when you’ve seen it 139 times.
In the meantime, Martine Cuypers gives us a swift and pithy guide to St Jerome’s Latin Bible, maybe the single most successful translation in the history of language.