| Quote #1 altar, sword, and pen, |
"Pen" here stands in for literature on the whole – Wordsworth puts literature up there as one of England's great traditions, along with things as important as religion and military might.
| Quote #2 Thou hadst a voice whose sound was like the sea: |
Here, Wordsworth means Milton's poetic voice. The wild, natural imagery of these lines emphasize the tremendous power and vast scope of Milton's work.