Matthew Poole and continuators on Exodus 16:19

19 And Moses said, Let no man leave of it till the morning .

viz. For the provision of the next day, as distrusting Gods care and goodness in giving them more. Not that every one was bound to eat all of it, which certainly many of their stomachs could not bear, but that they were to dissolve it, or burn it as they did the remains of some sacrifices, Exod. 12. 10. and 29. 34. or consume it some other way.