Only a man harrowing clods
In a slow silent walk
With an old horse that stumbles and nods
Half asleep as they stalk.
Only thin smoke without flame
From the heaps of couch-grass;
Yet this will go onward the same
Though Dynasties pass.
Yonder a maid and her wight
Come whispering by:
War's annals will cloud into night
The moral is stated clearly.  The grass is eternal, though power changes hands again and again, and control of the peasants' land goes from one government to the next. 
 Even though Hardy is writing of “Dynasties” with a capital “D,” he shows that their power can be broken by the forces of change. 
 In the first stanza, the word “Only” is coupled two lines later with “With” – only a man with his old horse. In this second stanza, “Only” is coupled with “Yet,” so we see that the stanza takes a turn at its middle. Smouldering weeds will burn longer than political control.
In Time of The Breaking of Nations