So, we'll go no more a-roving
So late into the night,
Though the heart be still as loving,
And the moon be still as bright.
For the sword outwears its sheath,
And the soul wears out the breast,
And the heart must pause to breathe,
And Love itself have rest.
Though the night was made for loving,
And the day returns too soon,
Yet we'll go no more a-roving
By the light of the moon.
The two lines together form the  antithetical  night and day, mystery and clarity, passion and sobriety — juxtaposed appropriately for impact
So well go no more a-roving