كَانَ اللَّهُ سَمِيعًا عَلِيمًا
And Allah is ever Hearing, Knowing.
In ordinary human statements, «كان» often locates a state in the past. With Allah’s attributes it must not be read as implying that the attribute ceased; the expression conveys enduring divine perfection.
A grammatical form cannot be interpreted apart from its subject and context. The same governing verb may carry a contextually appropriate nuance without implying the cessation of a divine attribute.