English of Core Text: “Let there be light” teaches that the light was created on the first day; even though it is written “and God set them in the firmament of the heaven” (on the fourth day), they were not suspended until the fourth day.
On the daf / in context: Within the first-day inventory the Gemara notes that the primordial light was created on day one but the luminaries were not hung in the firmament until day four.
Type of Learning: Custom (timing of light vs. luminaries)What Is Learned: The light of day one is distinct from the luminaries fixed on day four; the former was created immediately.