ROMEO Lady, by yonder blessed moon I swear
That tips with silver all these fruit-tree tops--
JULIET O, swear not by the moon, the inconstant moon,
That monthly changes in her circled orb,
Lest that thy love prove likewise variable.
ROMEO What shall I swear by?
JULIET Do not swear at all;
Or, if thou wilt, swear by thy gracious self,
Which is the god of my idolatry,
And I'll believe thee.
ROMEO If my heart's dear love--
JULIET Well, do not swear: although I joy in thee,
I have no joy of this contract to-night:
It is too rash, too unadvised, too sudden;
Too like the lightning, which doth cease to be
Ere one can say 'It lightens.' Sweet, good night!
This bud of love, by summer's ripening breath,
May prove a beauteous flower when next we meet.
Good night, good night! as sweet repose and rest
Come to thy heart as that within my breast!

-- William Shakespeare, Romeo and Juliet, Act II, Scene II