The love that was too poor to purchase you
Is rich enough to buy each noble thing,
That may be reached on the untiring wing
Of patient, strong pursuit; all that is true,
Honest, and brave, and most adorns a man,
I may achieve—and will:—and since I can
So glorify the life that you rejected,
E'en, fairest mistress! for your sake, no prize
That may proclaim me worthy, good, or wise,
Shall by my best endeavour be neglected.
So that this judgment you may yet decree,
When from the height of your sweet excellence,
You sentence pass, on my hope's bold offence—
Such love was worthy to be offered me.

Frances Anne Kemble

http://www.poemhunter.com/poem/a-rejected-lover-to-his-mistress-ii/