Thus is his cheek the map of days outworn,
When beauty lived and died as flowers do now,
Before these bastard signs of fair were born,
Or durst inhabit on a living brow;
Before the golden tresses of the dead,
The right of sepulchres, were shorn away,
To live a second life on second head;
Ere beauty’s dead fleece made another gay:
In him those holy antique hours are seen,
Without all ornament, itself and true,
Making no summer of another’s green,
Robbing no old to dress his beauty new;
And him as for a map doth Nature store,
To show false Art what beauty was of yore.
In plain English
The young man's face is like a record of times long past, when beauty was natural and fleeting like flowers. This was before fake ornaments—wigs made from the hair of the dead, stolen from tombs—became fashionable and people dared wear them on their living heads.
His beauty shows us what genuine, unadorned loveliness looked like in ancient times. He doesn't borrow from anyone else's youth to enhance his own, and he doesn't rob the old to dress himself up in stolen finery.
Nature keeps him as a living example, a map or blueprint, to show modern artificial beauty what the real thing actually was.
