Alexander Dyce, A General Glossary to Shakespeare's Works

deal “in her command, without her power,” THE TEMPEST, v. 1. 271. “Shakespeare, I conceive, had here in his thoughts vicarious and delegated authorities. He who ‘deals in the command,’ or, in other words, executes the office of another, is termed his lieutenant or vicegerent; and is usually authorized and commissioned to act by his superior. Prospero therefore, I think, means to say, that Sycorax could control the moon, and act as her vicegerent, without being commissioned, authorized, or empowered by her so to do” (MALONE) . “[We have here] the original and etymological sense of power or pouvoir; potestas, not vis; what we now call authority or legal power” (WALKER) . In this passage without her power has been explained “beyond her power,”—quite erroneously, I believe.