Clouds and eclipses stain both moon and sun,

And loathsome canker lives in sweetest bud.

(Sonnet 35.)

In an opposite sense is Sonnet 70:

The ornament of beauty is suspect

A crow that flies in heaven's sweetest air,

For canker vice the sweetest buds did love,

And thou presentest a pure unstained prime.

Sonnet 7 has:

Lo! in the orient when the gracious light