cannot be mentioned in the same breath; literally means one must not speak of two things on the same day because they are too different to be compared, especially when one is far superior to the other or has changed significantly from the past

(idiom) to speak of different things as if they were equal; often used in the negative to suggest that two things are not comparable; to mention in the same breath

to speak of things as being on par with one another; to compare things as if they were equal

literally translated as "must not speak of two things on the same day"; used to describe things that are so different they cannot be compared or mentioned in the same breath