Shakespeare's Sonnet 45

The other two, slight air, and purging fireAre both with thee, wherever I abide;The first my thought, the other my desire,These present-absent with swift motion slide.For when these quicker elements are goneIn tender embassy of love to thee,My life, being made of four, with two aloneSinks down to death, oppress’d with melancholy;Until life’s composition be recur’dBy those swift messengers return’d from thee,Who even but now come back again, assur’d,Of thy fair health, recounting it to me:This told, I joy; but then no longer glad,I send them back again, and straight grow sad.

The other two elements, weightless air and cleansing fire,
are both with you, wherever I may be.
The first is my thought, the second my desire;
here one moment, gone the next, they move swiftly.
For when these faster elements have left
to carry a tender message of love to you,
my life, made of four elements and left with only two,
sinks toward death, weighed down by sadness,
until its balance is restored
by those swift messengers returning from you.
They have just now come back, reassured
that you are well, and tell me so.
Hearing this, I rejoice, but my happiness does not last:
I send them back again and immediately grow sad.