Why should you swear I am forsworn, 
Since thine I vowed to be? 
Lady, it is already morn, 
And 'twas last night I swore to thee 
That fond impossibility. 
 
Have I not loved thee much and long, 
A tedious twelve hours' space? 
I must all other beauties wrong, 
And rob thee of a new embrace, 
Could I still dote upon thy face. 
 
Not but all joy in thy brown hair 
By others may be found;—  
But I must search the black and fair, 
Like skilful mineralists that sound 
For treasure in unploughed-up ground. 
 
Then if, when I have loved my round, 
Thou prov'st the pleasant she, 
With spoils of meaner beauties crowned 
I laden will return to thee, 
Ev'n sated with variety.
Richard Lovelace
http://www.poemhunter.com/poem/the-scrutiny/