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,
The construction of the last two lines are grammatically similar, an example of  syntactic parallelism . This creates a satisfying, gentle rhythm, ironically lyrical given that the speaker is bemoaning the after-effects of a debauched night. 
 
 This line forms the title of Ray Bradbury’s short story  “June 2001: —And The Moon Be Still As Bright”,  part of  The Martian Chronicles .
So well go no more a-roving