Moses told them not to keep any overnight.
Eat what you want that night, and the next morning burn whatever is left.
Some of them disobeyed, but the next morning what they kept was stinking and full of worms, and Moses was angry.
he told them that the LORD had said, “Tomorrow is the Sabbath, a sacred day of rest in honour of me. So gather all you want to bake or boil, and make sure you save enough for tomorrow.”
Do not offer bread made with yeast when you sacrifice an animal to me. And make sure that the fat of the animal is burnt that same day.
Don't worry about tomorrow. It will take care of itself. You have enough to worry about today.