> "Goldin skulu þér þessi orð áður þú ferð heim," segir Hallgerður.
> "You shall pay for these words before you go home," says Hallgerd.

That's right, and you all probably know this anyway, but just in case:
'ferð' is the Modern Icelandic equivalent of the 2nd person sg.
indicative present 'ferr'. The 'ð' comes from the pronoun 'þú', from
when it followed the verb, and was reinterpreted as part of the verbal
inflection. In fact, that's the opposite of what happened in the
medieval language with the 2nd person plural pronoun when 'ér' became
'þér', acquiring its initial consonant from the verb ending -ið.