Swords outwearing sheaths, souls outwearing breasts—this is a poem about getting worn out, in a lot of ways. Clearly the speaker is worn out from all his wandering (he's getting older, it's not really his thing anymore, etc.), and he uses the metaphors of the sword and the soul to explain it. The thing is, wearing things out is essentially a metaphor for death. Sheesh, and we though it was going to be a nice, happy, fun poem.
- Line 5: The word "for" (meaning "because") tells us that the metaphor of the sword outwearing its sheath is meant to explain why the speaker no longer wants to go roving. But is he the sword, or the sheath? If he's the sword, it means he's used up everything "roving" has to offer. If he's the sheath, roving has done a number on HIM. The vagueness leaves us wondering if he's a victim or not.
- Line 6: While we tend to think of the soul as residing somewhere inside our chest cavities, breast might also here be an example of synecdoche. The idea of the soul leaving the body is a metaphor for death—according to many religions, when we die, the soul leaves the body and goes… wherever souls go.
- Line 7: If the heart needs to breathe, it sounds like it's getting a little worn out. The heart here is a symbol for one's emotions, or a metaphor for the place where one's emotions are often said to reside.