A Sonnet (or short poem) from a collection written by William Shakespeare, published in 1609. 

#22

Synopsis:

This sonnet plays with the poetic idea of love as an exchange of hearts. The poet urges the young man to take care of himself, since his breast carries the poet’s heart; and the poet promises the same care of the young man’s heart, which, the poet reminds him, has been given to the poet “not to give back again.”

My glass shall not persuade me I am old

So long as youth and thou are of one date,

But when in thee Time’s furrows I behold,

Then look I death my days should expiate.

For all that beauty that doth cover thee

Is but the seemly raiment of my heart,

Which in thy breast doth live, as thine in me;

How can I then be elder than thou art?

O, therefore, love, be of thyself so wary

As I not for myself but for thee will,

Bearing thy heart, which I will keep so chary

As tender nurse her babe from faring ill.

 Presume not on thy heart when mine is slain.

 Thou gav’st me thine not to give back again.

(Project Gutenberg, Public Domain)