| It tore the elm-tops down for spite (3) |
The power of the storm is personified in the opening lines of the poem. It's important to remember, though, that the poem is written from the point of view of a very unstable mind.
| When glided in Porphyria: straight |
Despite the awesome power of the storm, Porphyria seems to be able to "shut [it] out" almost without effort.
| […] she |
Love, as we've seen, is figured in terms of freedom and constraint. Porphyria's "weak[ness]" here suggests that she's neither as powerful nor as free as she seemed at the beginning of the poem.
| Nor could tonight's gay feast restrain (27) |
Again, the metaphor of freedom and restraint! The power of Porphyria's love for the speaker made her skip a party. She simply couldn't "restrain" the urge to visit him.
| And all night long we have not stirred, |
This reference to God is the only suggestion of an outside system of ethics in the poem. It almost seems to be a taunt, as though the speaker laughs at the idea of any kind of retribution.