Sforno on Exodus 16:25/ספורנו על שמות ט״ז:כ״ה

1אכלוהו היום, at fixed times, from this date onward.

2'כי שבת היום לה, this entire day is a Sabbath in honour of G’d. It was permitted to eat any manna left over from Friday on the entire Sabbath. However, if any was left over after the Sabbath it could not be eaten anymore.

3היום לא תמצאוהו, on the entire Sabbath you will not find any manna on the ground anywhere just as you did not on this Sabbath.