> Þórólfur mælti við Ásgaut:Small point: in this context <mæla við> is 'to speak to'.
> Þórólfr spoke with Ásgautr:
> Eftir það ganga þeir ofan fyrir höfuðísinn ...<Ofan fyrir> is 'down over' (see Z. s.v. <ofan>).
> After that they walk down before the ice-masses ...
> ... komast þeir yfir ána ...In this case <yfir> is 'across' (and also in the next
> ... they made-their-way over the-river ...