As for the apparent wording, there is no doubt that, by common agreement, it is understood otherwise. Yet it is not conceded that this is what ordinary Muslims who use and hear this expression naturally understand, or that it is what the wording means in Arabic, as may be explained at length elsewhere.
He, Exalted is He, has said:
“Say, ‘No one in the heavens and the earth knows the unseen except Allah.’”
He thus excepted Himself, while “whoever is in the heavens and the earth” is the subject of “knows.” It cannot be said that this is a disconnected exception, because the excepted noun is nominative; had the exception been disconnected, it would have been accusative. Its nominative case is due to apposition, and its grammatical governor is the same as that of the expression to which it stands in apposition. This is equivalent to an elliptical exception construction, as though He had said, “No one knows the unseen except Allah.” It follows that He is included within “whoever is in the heavens and the earth.”
We have already explained that the word “heaven” encompasses everything that is high: it includes the heavens, the Footstool, the Throne, and whatever is above that. For this occurs within a negative statement, and He did not say here “the seven heavens”; rather, He used the unrestricted expression “the heavens.”
Since “heaven” may mean the clouds, the celestial sphere, what is above the world, or height in an unrestricted sense, “heavens” is the plural of “heaven.” No one in anything called “heaven,” and no one in anything called “earth,” knows the unseen except Allah.