These words were spoken upon the morning of the sabbath day, as appears from the foregoing verse. A sabbath unto the Lord, i.e. wholly consecrated to his service, and therefore not to be employed in servile works.
Related Commentaries of Exodus 16:25
Exodus 16:25
25 And Moses said, Eat that to day; for to day is a sabbath unto the LORD: to day ye shall not find it in the field.