PL 100, col. 520A
Question 33. Why is light read to have been created on the first day? — Answer. It befits the works of God that on the first day a temporal light should first be made from the eternal light, so that there might be something from which the rest that he would create could appear.
Fresh draft (Claude), approved by Wilson Pruitt · cc-by
PL 100, col. 520A · pd
Bede's sentence reduced to a schoolroom answer, with one word added that is not Bede's and that does the work: a luce aeterna, from the eternal light. Bede had set the eternal light beside the material one; Alcuin makes the temporal light come out of it, which is a claim about derivation and not merely about order. Compare Pirkei de-Rabbi Eliezer, where the heavens are made out of the light of God's garment: on both benches the first light acquires a source in God himself, and on neither is that reading argued for.