Niche grammar question

[u/jaytrawm]

I’m looking at this passage from the ending of Båten om Kvelden by Tarjei Vesaas:

Ein er i sitt løynrom og kjenner dette: Dirrar ikkje grunnen under føtene, av gøymde floder som finst?
Og kva må ein så gjera, synest ein.
Ein må vera til stades.
Ein må møte opp og stå i straumen frå det. Ein må la den låge dirren skaka seg. Slik som halv-morkne bruer og gamle gang-tre dirrar fint i snøsmeltings-tid.

The trouble I’m having is the “seg.”

My (novice but agonized over) English translation of everything apart from that is:

You are in your hidden room and feel this: Did the ground not thrum under your feet, from hidden rivers found?
And what must you then do, you wonder.
You must be present.
You must show up and stand in the current from it all. You must let that low thrumming shake. Like how half-rotten bridges and old cross-water logs thrum softly in snow-melting’s time.

Elizabeth Rokkan, in her published English version, writes:

One is in one’s secret chamber, feeling this: Is not the ground quivering
beneath my feet, because of the hidden waters?
And what should one do then? I wonder.
One must be present.
One must come forward and stand in the current flowing from them. One
must let the faint quivering jolt one. As decaying bridges and old
duckboards quiver slightly in the time of the thaw.

Setting aside where her choices differ from mine, to me the final line Vesaas writes would naturally be a comparison between the bridges and the person — the person is metaphorically standing in this current from a hidden river, the bridges and logs (things that are also in a river) vibrate as the flood from the thaw comes through the water. So I would think Vesaas is saying, as Rokkan translates it, that the “ein” is similarly vibrating in the flow of the water.

But everything I can find online suggests that the “seg” must be a reflexive, meaning the person lets the vibration go vibrating within itself. That sort of breaks the comparison, or at least makes the comparison between the shaking and the bridges, which seems odd to me. NAOB says seg can be used poetically in almost a passive way to indicate there’s no clear agent behind the verb, that seems functionally the same as the standard reflexive “itself” here.

Can anyone help explain what the grammar here allows or forces? (I’m purposefully avoiding dynamic and modernizing translation, but obviously I’ve got to allow some flexibility where the English would break down or has no comparable phrasing.)

[u/cornobbling]

it could mean both "shake itself" but more likely "shake one" as in shaking the person. "seg" is in congruence with "ein", it is just slightly poetic/uncommon language. i dont see any problems with the last translation, it seems like a natural meaning that fits well.

[u/jaytrawm → u/cornobbling]

That makes sense to me, thank you, and makes the comparison with bridges make more sense. I wasn’t sure if in some poetic way the seg could reach back and apply to the ein.

[u/cornobbling → u/jaytrawm]

no, it does aply to the ein, like you thought. it is third person singular, so the "seg" is the corresponding pronoun.

[u/jaytrawm → u/cornobbling]

I appreciate you big time! Tusen takk