Then He clarified piety by describing them with His saying: "Those who fear". This means they fear with a great fear their Lord, who is the Benefactor to them after creation through nurturing and various kinds of goodness. "In the unseen" means before He uncovers the veil for them. "And they are from the Hour" which we will establish the scales in. The ignorant have turned away from it, despite it being the greatest motivator for every good and the greatest deterrent from every harm. "They are apprehensive" because they are certain of its occurrence, and by the establishment of the scales in it, they are knowledgeable.