Analysis of Sonnet LI: I Must Not Grieve My Love

I must not grieve my Love, whose eyes would read
Lines of delight, whereon her youth might smile;
Flowers have a time before they come to seed,
And she is young and now must sport the while.
Ah, sport, sweet Maid, in season of these years,
And learn to gather flowers before they wither;
And where the sweetest blossoms first appears,
Let love and youth conduct thy pleasures thither.
Lighten forth smiles to clear the clouded air
And calm the tempest which my sighs do raise;
Pity and smiles do best become the fair;
Pity and smiles shall yield thee lasting praise.
I hope to say, when all my griefs are gone,
Happy the heart that sigh'd for such a one.