John Gill Commentary Exodus 16:5

"And it shall come to pass on the sixth day, that they shall prepare that which they bring in, and it shall be twice as much as they gather daily." — Exodus 16:5 (ASV)

And it shall come to pass, that on the sixth day
Of the week, and from the raining of the bread, which was on the first day of the week:

they shall prepare that which they bring in ;
the Targum of Jonathan adds, to eat on the sabbath day; what they did not consume on the sixth day was to be prepared and reserved for the seventh day; that is, it was to be baked or boiled as they thought fit to have it, or eat it as it was, which they pleased, see (Exodus 16:23) only one part of it was to be kept till the next day:

and it shall be twice as much as they gather daily :
on that day should be rained double what fell on other days, and so twice as much should be gathered up; the reason for which is not here mentioned, but afterwards given; though Moses no doubt was now made acquainted with it, or otherwise he could not have informed the princes and people of it, as he afterwards did, (Exodus 16:23Exodus 16:25Exodus 16:26Exodus 16:29) .