Why I tie about thy wrist,
Julia, this my silken twist?
For what other reason is't,
But to shew thee how in part
Thou my pretty captive art?
But thy bond-slave is my heart;
'Tis but silk that bindeth thee,
Knap the thread and thou art free;
But 'tis otherwise with me;
I am bound, and fast bound so,
That from thee I cannot go;
If I could, I would not so.

Robert Herrick

http://www.poemhunter.com/poem/the-bracelet-to-julia-2/