Can it be said regarding other volitional attributes such as wrath, mercy, and descending: that it is an essential attribute in terms of its type, and a volitional one in terms of its individual instances, just as is said concerning the speech of Allah?

The inherent, active attribute of God, such as speech, creation, and sustenance, is that by which God has always been characterized (ancient in kind), and its individual manifestations are renewed according to His will (active). The descent to the lowest heaven is an active attribute, not eternal in its kind or its individual manifestations, because it occurred after the existence of the lowest heaven. Some scholars consider the genus of action to be eternal, while the descent is a contingent or renewed event. The descent is a type of action that is contingent because it occurred after the creation of the lowest heaven.