And it was commanded them; that is, these locusts; God so ordered it by his providence. That they should not hurt, &c.: this makes it appear, that these locusts were no insects so called, but typical; for natural locusts live upon green things; they were only to hurt profane men, and hypocrites. It is a sure rule, that when things are attributed: to living creatures which do not agree to their natures, the terms are to be understood typically, not literally. Locusts use not to kill men; we may therefore be assured, that the locusts here intended, were men, not insects.
Related Commentaries of Revelation 9:4
Revelation 9:4
4 And it was commanded them that they should not hurt the grass of the earth, neither any green thing, neither any tree; but only those men which have not the seal of God in their foreheads.