What does this sentence from the Tempest mean?

Question

This is a quote from "the Tempest" by Prospero:

This misshapen knave, His mother was a witch, and one so strong That could control the moon, make flows and ebbs, And deal in her command without her power.

And it translates to (according to this source):

This ugly monster had a mother who was a witch so powerful that she could control the moon and the tides.

To me that translation is pretty much correct but it explains the meaning of the original sentence until the "make flows and ebbs" part. What does the next part of the original sentence mean? And shouldn't translation of a literary work be done with full fidelity?

Answer 1

According to the footnotes in a version of The Tempest edited by Horace Howard Furness, and published in 1892:

"He who 'deals in the command,' or, in other words, executes the office of another, is termed his lieutenant or viceregent, and is usually authorised and commissioned to act by his superior. Prospero therefore, I think, means to say that Sycorax could control the moon and act as her viceregent, without being commissioned, authorised or empowered by her so to do." (his emphasis)

What this would suggest is that "deal in her command", means to control the moon, or use the power of the moon, while "her power" is the moon's power/authority (the moon is given feminine grammatical gender), which Sycorax does not need to control tides etc.