> en það mundi eg vilja að eg hefndi þessa á þeim nokkurum er hann brenndu inni er nú hefir mig hent."
"but I would like to take vengence for this thing that has just now happened to me on some of those who burnt him in his home"
'henda', Z3 "befall, happen to one". The neuter singular past participle has the same form as that of 'henta' "to befit", but 'henta' takes a dative object for the person it befits, whereas 'henda' takes accusative for the person it happens to.
> ekki taka mega af því hvað mælt væri.
"would not be able to take away from what would be said" (i.e. wouldn't be able stop people speaking [negatively] of it).
> Ásgrímur sagði það mikinn afla.
"Ásgrímur declared that [to be] great strength", or "a powerful force". This is the accusative noun 'afli', rather than the infinitive of the verb 'afla'.