'Pouring out the vials upon the earth, which contained the plagues,' in Revelation 16:1, signifies influx of the reformed into the church, or into people who study and receive the doctrine of justification by faith alone.

(Reference: Apocalypse Explained 16; Apocalypse Revealed 676)

To command is to give an order that something must be done, and is directed to an individual, or a group. It is an imperative, not a suggestion. Commanding can be done in two ways, or from two differing motives. It often comes in an organization, where it is used to impose an order that is necessary to do the organization's work, such as a business, or government or an army, and can be legitimate, or is used in a family by parents to maintain an orderly home. But it can also be used by a person who loves power and having gotten it in some way, loves to impose his or her will on others for selfish gratification. So one motive is love of a use, or of good, and the other is for the love of self, or possessions. The Lord, from His infinite love, has given mankind commandments because He is order itself, and knows that our happiness to eternity depends on our acceptance of His order of creation, which ultimately is the only order that exists.