attribute one might mention that a person must be aware of in order to be aware of the essence.
A servant may remember his Lord without it occurring to him at that moment that He is eternal and without beginning, enduring and without end, necessarily existent in Himself, self-subsisting, or anything else of this kind. Likewise, the bodies he observes may come to mind without his considering whether they occupy space or not.
If you mean the second, it is well known that a person cannot know Allah with the knowledge required by the revealed Law, the knowledge attainable by human beings, or complete knowledge, until he knows that He is living, all-knowing, and powerful. For someone who knows that Allah possesses these attributes, when His essence and these attributes come to mind, it is impossible to suppose that His essence could exist in external reality without these attributes. Likewise, it is impossible to suppose that His essence could exist in external reality without being eternal, necessarily existent, and self-subsisting.
Thus, with respect to all His attributes inseparable from His essence—exalted is He—when one conceives of the attribute and its possessor and knows that the attribute necessarily belongs to its possessor, it is impossible to suppose that the essence could exist without its inseparable attributes while knowing this necessary connection. If, however, one supposes that this necessary connection is unknown, or that the inseparable attributes do not come to mind, then the essence can come to mind without any of these attributes.
If one knows that some attributes necessarily belong to the essence but does not know this of others, one cannot suppose that the essence could exist without those attributes whose necessary connection to it is known. As for an attribute whose necessary connection is unknown, the mind can suppose that the essence exists without that attribute. Yet this possibility means not knowing it to be impossible, rather than knowing it to be possible in external reality, since whatever a person does not know to be nonexistent is possible in his judgment