Here´s my translation.

I am wondering if there is any subtle difference between: það er að ben gerðist and því sári er að ben gerðist, because MM/HP´s translation does not seem to make a distinction..

Also with veita, the object sár (neut) is acc. sg but with lýsa the object sári is dat sg. I can only conclude, therefore, that heilundar, holundar and mergundar which all seem to be fem gen sg are genitives of specification (of identity) (see Z157), linked to sár either explicitly, in the case of heilund, or implicitly in the case of holund and mergund. I would be grateful for any clarification on this matter.

Kveðja

Alan

Í annað sinn nefndi Mörður sér votta "í það vætti," segir hann, "að eg lýsi
For another time (ie again), Mörð named for himself witnesses ‘in that testimony,’ says he, ‘that I proclaim

lögmætu frumhlaupi á hönd Flosa Þórðarsyni er hann veitti Helga Njálssyni
a punishable personal-assault against (see á hönd, Z1) Flosi Þórð’s-son when he inflicted on (see veita e-m áverka, Z7) Helgi Njál’s-son

heilundar sár eða holundar eða mergundar það er að ben gerðist en Helgi fékk
a brain-wound or body-penetrating-wound or marrow-wound, that which was made into (became, turned out to be) a mortal wound but (and) Helgi received

bana af. Lýsi eg fyrir búum fimm" - og nefndi hann þá alla - "lýsi eg
death from (it). I proclaim (it) before five neighbours ‘- and he named them all – ‘I proclaim

löglýsing. Lýsi eg handseldri sök Þorgeirs Þórissonar."
a legal-proclamation (declaration). I proclaim (the) suit-conducted-by-proxy from Þorgeir Þóri’s-son.’


Í öðru sinni nefndi hann votta "í það vætti að eg lýsi heilundarsári eða
For another time (again) he named witnesses ‘in that testimony that I proclaim a brain-wound or

holundar eða mergundar á hönd Flosa Þórðarsyni, því sári er að ben gerðist
body-penetrating-wound or marrow-wound against Flosi Þórð’s-son, with that wound which was made into (became) a mortal-wound

en Helgi fékk bana af á þeim vettvangi (vættvangr) er Flosi Þórðarson hljóp til Helga
but (and) Helgi received death from (it) at that spot-where-an-assault-took-place when Flosi Þórð’s-son sprang towards Helgi

Njálssonar lögmætu frumhlaupi áður. Lýsi eg fyrir (before, ie in the presence of, I think) búum fimm" - síðan nefndi
Njál’s-son in a punishable personal-assault before (previously, earlier). I proclaim (it) before five neighbours’ – after-that he named

hann þá alla - "lýsi eg löglýsing. Lýsi eg handseldri sök Þorgeirs
them all – ‘I proclaim a legal-proclamation (declaration). I proclaim (the) suit-conducted-by-proxy from Þorgeir

Þórissonar."
Þóri’s-son.’


Þá nefndi Mörður sér votta hið þriðja sinn "í það vætti," segir hann, "að eg
Then Mörð named for himself witnesses the third time ‘in that testimony,’ says he ‘that I

kveð (kveðja, takes genitive, see following) vettvangsbúa þá  (acc masc pl of sá, rather than then) alla níu" - og nefndi þá alla á nafn - "alþingisreiðar (fem gen sg with kveðja, see Z1)
summon (call on) neighbours-to-the-scene-of-action, all those nine’ – and named them all by name – ‘for (ie to make)-a-journey-to-(the)-Althing

og búakviðar (masc gen sg with kveðja, see Z1) að bera um það hvort Flosi Þórðarson hljóp lögmætu frumhlaupi
and for (ie to make) the verdict-of-neighbours  and to adjudicate about that (see bera um e-t, Z7) whether Flosi Þórð’s-son sprang in a punishable personal-assault

til Helga Njálssonar á þeim vettvangi er Flosi Þórðarson veitti Helga
towards Helgi Njál’s-son at that spot-where-an-assault-took-place when Flosi Þórð’s-son gave Helgi

Njálssyni heilundarsár eða holundar eða mergundar það er að ben gerðist en
Njál’s-son a brain-wound or body-penetrating wound or marrow-wound, that which was made into (became) a mortal-wound but (and)

Helgi fékk bana af. Kveð (kveða rather than kveðja?) eg yður þeirra orða allra er yður skylda lög til um
Helgi received death from (it). I recite to you all those words which oblige you, according to law,

að bera og eg vil yður að dómi beitt (pp of beiða?) hafa og þessu máli eiga að fylgja. Kveð (kveða rather than kveðja?)
to adjudicate and I want to have requested to you to (the) court and to have to (must) accompany this case. I recite

eg yður lögkvöð svo að þér heyrið á sjálfir. Kveð eg um handselt (pp of handselja) mál
you to a legal-summons so that you hear (it) yourself. I recite concerning (the) made-over case

Þorgeirs Þórissonar."
of Þorgeir Þóri’s-son.’


Mörður nefndi sér votta "í það vætti," segir hann, "að eg kveð vettvangsbúa
Mörð named for himself witnesses ‘in that testimony,’ says he that I summon neighbours-to-the-scene-of-the-action,

þessa níu alþingisreiðar (fem gen sg with kveðja) og búakviðar (masc gen sg with kveðja)að bera um það hvort Flosi Þórðarson
these nine, to (make) a riding-to-(the)-Althing and to (make) a verdict-of-neighbours to adjudicate concerning that, whether Flosi Þórð’s-son

særði Helga Njálsson heilundarsári eða mergundar eða holundar, því sári er
wounded Helgi Njál’s-son a brain-wound or marrow-wound or body-penetrating wound, with that wound

að ben gerðist en Helgi fékk bana af á þeim vettvangi er Flosi Þórðarson
which was made into (became) a mortal-wound but (and) Helgi received death from (it) at that that spot-where-an-assault-took-place when Flosi Þórð’s-son

hljóp til Helga Njálssonar áður lögmætu frumhlaupi. Kveð eg yður þeirra orða
sprang towards Helgi Njál´s-son before (already, previously) in punishable personal-assault. I recite to you all those words

allra er yður skylda lög til um að bera og eg vil yður að dómi beitt (pp of beiða?) hafa og
which oblige you, according to law to adjudicate and I want you to have request at (the) court and

þessu máli eiga að fylgja. Kveð eg yður svo að þér heyrið á sjálfir. Kveð eg
to have to follow this case. I recite (it) to you so that you hear (it) yourself. I summon (call on)

yður um handselt mál Þorgeirs Þórssonar."
you concerning (the) made-over case of Þorgeir Þóri’s-son.’