there are a stealing refreshment?

While i was reading a poem by Jone Galsworthy ( winner of 1932 Nobel prize in literature), i came across one sentence : "They are a stealing and silent refreshment that we perhaps do not think about, but which goes on all the time. "

I am just wondering why in that sentence the writter use " a stealing and silent refreshment" after " they are" ? I understand if the sentence was " there is a stealing and silent refreshment.."  but now i am confused. Someone please tell me what grammar is uesed here? thanks in advance!

Here it is:

A choirboy's voice, a ship in sail, an opening flower, a town at night, the song of the blackbird, a lovely poem, leaf shadows, a child's grace, the starry skies, a cathedral, apple trees in spring, a throughbred horse, sheep-bells on a hill, a rippling stream, a butterfly, the crescent moon--the thousand sights or sounds or words that keep the human spirit from death by drought. They are a stealing and silent refreshment

 

 

LOL! Neither do I!    (Hyperplural?)

(maybe there are even too many of them for a stealing refreshment)

"they" is a completely different word from "there".
"they", which means "those things (or people) mentioned before", is used in the poem, not "there".
When the subject is "they", the verb is plural -- "are" in this case.
So "They are a ..." in the poem is correct.
(Your subject line is incorrect.)

Hope that helps. 
CJ