Sonnet 50 BLOODY SPUR: How heavy do I journey on the way

How heavy do I journey on the way,
When what I seek, my weary travel's end,
Doth teach that ease and that repose to say,
'Thus far the miles are measured from thy friend!'
The beast that bears me, tired with my woe,
Plods dully on, to bear that weight in me,
As if by some instinct the wretch did know
His rider lov'd not speed being made from thee.
The bloody spur cannot provoke him on,
That sometimes anger thrusts into his hide,
Which heavily he answers with a groan,
More sharp to me than spurring to his side;
   For that same groan doth put this in my mind,
   My grief lies onward, and my joy behind.

It's a sweet image of a sullen Shakespeare
on a horse plodding down the road

You can feel the weight of time: the wait
heavy, weary, tired with woe, plods dully on...
The meter resounding like horse's hooves on the road
lugubrious lamentation in alliteration
when what weary woe weight wretch
mile measured
beast bears bear bloody
and those two bears!
wretched beastly bears
then the bloody spur
singing out in Q3
anger, what anger? where?
weren't we weary with woe?
but with the turn comes anger
perhaps for having to leave London
and travel back to Stratford
to the wife and kids
to the million little pricks
and that groan
this sadistic Shakespeare
full of such anger as to bloody a spur
in a horse's hide
seems incongruous and yet all too human
rationalized that the greater pain is his
that same groan
you wonder at the sound
the recalcitrant horse
Rocinante
the angry Poet
spurs jingling on his boots
wheels spinning
dripping with hot red blood
but which cause no difference in the horse's pace
there's a sonnet to be written about this horse
and his evocative groan