Shakespeare's Sonnet 17

Who will believe my verse in time to come,If it were fill’d with your most high deserts?Though yet heaven knows it is but as a tombWhich hides your life, and shows not half your parts.If I could write the beauty of your eyes,And in fresh numbers number all your graces,The age to come would say ‘This poet lies;Such heavenly touches ne’er touch’d earthly faces.’So should my papers, yellow’d with their age,Be scorn’d, like old men of less truth than tongue,And your true rights be term’d a poet’s rageAnd stretched metre of an antique song:But were some child of yours alive that time,You should live twice,—in it, and in my rhyme.

Who in the future will believe my verse if I fill it with the praise you truly deserve? Yet heaven knows it is only like a tomb that hides your life and reveals less than half your qualities.
If I could describe the beauty of your eyes and count all your charms in fresh verse, future generations would say, “This poet lies. Such heavenly beauty never appeared on an earthly face.”
So my pages, yellow with age, would be mocked like old men who talk more than they tell the truth. The praise you rightly deserve would be called a poet's wild exaggeration and the overblown verse of an old-fashioned song.
But if a child of yours were alive then, you would live twice: in your child and in my verse.