These have power to shut the heaven that no rain may fall during the days of their prophecy; and they have power over the waters to turn them into blood, and to smite the earth as often as they will with every plague.
Ginomai: aorist. Has now taken place, begun to be.
Or 'who sat.' It is characteristic, without reference to time, save as he had seen them (ch. 4.4); 'the sitters on thrones.' I put only 'sit,' because the scene is present, though the actions follow one another.