In the fifth verse (61), mention has been made of the all-encompassing knowledge of the most exalted Allah and its unmatched multi-dimensional extensions. The address is to the Holy Prophet ﷺ . He is being told that nothing he does by way of his work or recital of the Qur'an remains hidden from Allah. Similarly, whatever all human beings do remains before Him. And not even a single particle in the heavens and the earth is concealed from Him. Rather, everything is written in the clear Book, that is, the Preserved Tablet (al lawh al-mahfuz).
At this place, as it seems, the wisdom of describing the all-encompassing nature of Divine knowledge is aimed at consoling the Holy Prophet ﷺ that his enemies cannot harm him in any way for he was under the protection of Allah Ta` ala.