WE see them not--we cannot hear
   The music of their wing--
Yet know we that they sojourn near,
   The Angels of the spring!

They glide along this lovely ground
   When the first violet grows;
Their graceful hands have just unbound
   The zone of yonder rose.

I gather it for thy dear breast,
   From stain and shadow free:
That which an Angel's touch hath blest
   Is meet, my love, for thee!

Robert Stephen Hawker

http://www.poemhunter.com/poem/are-they-not-all-ministering-spirits/