Devouring Time, blunt thou the Lion's paws,
And make the earth devour her own sweet brood;
Pluck the keen teeth from the fierce tiger's jaws,
And burn the long-lived phoenix in her blood;
Make glad and sorry seasons as thou fleet'st,
And do whate'er thou wilt, swift-footed Time,
To the wide world and all her fading sweets;
The opening four lines show the power of Time, which has an effect on every living being. Even creatures such as the  phoenix  which were seen as immortal in Greek mythology, renewing themselves periodically through immolation and re-birth, die eventually. 
 
 Modern readers will be familiar with Dumbledore’s Pheonix, Fawkes, in the Harry Potter series.
Sonnet 19