ZEITGEIST the poem ekossigan left

Asrabey Varal tells the King and the RHC constables:

His name is Ekossigan, herald of the four seasons, he who defends stags from arrows, widdershins prophet, and liege of changelings.

Upon leaving the Court he penned this poem:

“When spring returns to winter, / The cauldron births a spark.
“The steel betrays the vintner, / The silver spurns the arc.
“The fire-bride’s dissension: / Dismissed by green-adorned.
“The wheel-woven dead man / Shall wake the cauldron-born.

My party ist killing themselves to get some insight from that and keeps asking me. Unfortunately i have little clues about the two middle lines myself.

I get the reference to the cauldron (Borne getting out of Cauldron Hill maybe by some action that Grappa could initiate?) and spring turning to winter (as some reference about Ekossigan going to prevent the birth of Borne?) mostly but what is the meaning of the poem? I know that Ekossigan is more or less unhinged and wonder if there is meaning in every part?

If the question is already answered somewhere else in the forum, would you kindly point me there?

When spring returns to winter = Ekossigan of spring turning into his more morbid winter incarnation
The cauldron births a spark = It's gonna bloooooooow
The steel betrays the vintner = Born can't be controlled by Leone (his family has some vineyards and he's mentioned to appreciate good wine)
The silver spurns the arc = Risuri idiom related to silver arc of Reida, plane of time. Approx. "the time are a-changing"
The fire-bride’s dissension: / Dismissed by green-adorned. = Accusation of Leya's involvement with Ob are dismissed by the king, who insists on peace talks with Danor.
The wheel-woven dead man / Shall wake the cauldron-born. = Grappa has an absent-minded son to wake. (I'm sorry for this joke.)


Also check this post and reply by Ryan two posts below

Thank you very much.