He Must Be Wicked To Deserve Such Pain

This is a great story poem by Robert Browning.  Here's the whole thing.  The line is from Shakespeare's King Lear, so says Wikipedia.

Childe Roland to the Dark Tower Came

My first thought was, he lied in every word.  

   That hoary cripple, with malicious eye

   Askance to watch the working of his lie 

On mine, and mouth scarce able to afford 

Suppression of the glee, that pursed and scored

   Its edge, at one more victim gained thereby.

[...] 

As for the grass, it grew as scant as hair

   In leprosy; thin dry blades pricked the mud

   Which underneath looked kneaded up with blood.

One stiff blind horse, his every bone a-stare,

Stood stupefied, however he came there:

   Thrust out past service from the devil's stud!

[...]

Seldom went such grotesqueness with such woe;

I never saw a brute I hated so;

   He must be wicked to deserve such pain.