English of Core Text: The “one day” spoken of in the account of creation — the day follows the night, as it is said “and there was evening and there was morning, one day.”
On the daf / in context: In the context of the law that a day’s offerings or counts begin from the preceding night, the creation order is cited as the model: night precedes day.
Type of Learning: Custom (night precedes day in the creation model)What Is Learned: In the Torah’s creation accounting, the day is defined as night followed by daytime.