Exodus 16:22-23

And it came to pass, that on the sixth day they gathered twice as much bread, two omers for each one: and all the rulers of the congregation came and told Moses. And he said unto them, This is that which Jehovah hath spoken, To-morrow is a solemn rest, a holy sabbath unto Jehovah: bake that which ye will bake, and boil that which ye will boil; and all that remaineth over lay up for you to be kept until the morning.