Oh, stay that covetous hand; first turn all eye,
All depth and minde; then mystically spye
Her soul's faire picture, her faire soul's, in all
So truely copied from th' originall,
That you will sweare her body by this law
Is but its shadow, as this, its;--now draw.

Richard Lovelace

http://www.poemhunter.com/poem/upon-the-curtain-of-lucasta-s-picture-it-was-thu/