ON TIME

Fly, envious Time, till thou run out thy race;
Call on the lazy leaden-stepping hours,
Whose speed is but the heavy plummet’s pace;
And glut thyself with what thy womb devours,
Which is no more then what is false and vain,
And merely mortal dross;
So little is our loss,
So little is thy gain…

– John Milton

(Those are just the opening lines; the whole thing is here.)