Shakespeare's Sonnets: Whil'st I alone did call upon thy aid

Whil'st I alone did call upon thy aid,My verse alone had all thy gentle grace,But now my gracious numbers are decay'd,And my sick muse doth give an other place.I grant (sweet love) thy lovely argumentDeserves the travail of a worthier pen,Yet what of thee thy poet doth invent,He robs thee of and pays it thee again.He lends thee virtue, and he stole that wordFrom thy behaviour; beauty doth he giveAnd found it in thy cheek; he can affordNo praise to thee but what in thee doth live. Then thank him not for that which he doth say, Since what he owes thee, thou thy self dost pay.