He told them, “This is what the LORD has said: ‘Tomorrow is to be a day of complete rest, a holy Sabbath to the LORD. So bake what you want to bake, and boil what you want to boil. Then set aside whatever remains and keep it until morning.’”
We have here, 1. A plain intimation of the observing of a seventh day sabbath, not only before the giving of the law upon Mount Sinai, but before the bringing of Israel out of Egypt, and therefore, from the beginning, Gen 2:3.
Commenting on Exodus 16:22-31
And they laid it up until the morning, as Moses bade,.... What was left of two omers a man, what they had neither baked nor boiled: and it did not stink, neither was there any worm therein, which was the case, when it was left or laid up on other days; and it showed that there was an interposition of divine Providence in the keeping...
To-morrow is the rest of the holy Sabbath - There is nothing either in the text or context that seems to intimate that the Sabbath was now first given to the Israelites, as some have supposed: on the contrary, it is here spoken of as being perfectly well known, from its having been generally observed.