How we cite our quotes: (Line)
Quote #1
to be filled
by my vanity, my love,
my hope, my body. (3-5)
Ah, this is where it all begins. The suit, which has been waiting on the chair while the speaker showers, is ready to be filled with the speaker's vanity, love, hope, and body. Whew, that's a lot of stuff to fit into one suit. It's no wonder that the speaker changes the suit from merely fabric into something resembling himself when he puts it on. We just don't know what it'll transform into (not yet, anyway).
Quote #2
my legs seek
the hollow of your legs,
and thus embraced
by your untiring loyalty (10-13)
Using personification, Neruda lets us see that the suit is already becoming more human. It has its own legs, though they are hollow, but referring to them as "legs" doesn't necessarily mean we think they are alive. It's the use of "your" that reminds us that Neruda is addressing the suit. They then "embrace." The suit has transformed into something that can return affection. It's more than just a suit (after all, how can a piece of clothing be "loyal")? The speaker is beginning to consider the value of the suit; it's transforming into something more than just a nice cut of fabric.
Quote #3
I am shaping you,
poking out your elbows, (27-28)
The speaker compares the "shaping" that the world does on him to how he shapes the suit. The more he wears it, the more it wears out. But perhaps, it also becomes more comfortable, more fitted to his body. This transformation mirrors the transformation he is going through in his own life, as events and struggles wear him down and "shape" him. Life wears him and transforms him, just as he wears and transforms his suit.