'Twere profanation of our joys
To tell the laity our love. (7-8)
Donne's speaker isn't just being a snob here, saying that commoners couldn't understand their love. He's saying that, if they broadcast all their heartache at separating, it would trivialize the joy they still share in their love.
But we, by a love so much refined […]
Care less eyes, lips and hands to miss. (17-20)
Like we said, for Donne, love is unstoppable. It certainly can't be held back simply by taking away physical presence.
Though I must go, endure not yet
A breach, but an expansion (22-23)
Love is powerful. It's also inexhaustible. Shakespeare said it in Romeo and Juliet: the more love you give away, the more you find you have. So when two true lovers part from one another, their love doesn't break in half, it expands.
Thy soul, the fix'd foot, makes no show
To move, but doth, if th' other do. (27-28)
Talk about being joined at the hip… er, compass. This metaphor underscores the powerful bonds of love: if one part of the pair moves, the other must move as well.
Thy firmness makes my circle just,
And makes me end where I begun. (35-36)
Everything comes full circle at the end of the poem, with the promised reunion. Importantly, it's the wife of the speaker (specifically her "firmness" in his absence) that will be responsible for bringing him back and reuniting their love. Aww.