> því aðeins ferjanda né festum helganda nema fjörbaugur eða aðalfestur komi fram að féránsdómi

"not to be ferried (not legally ferriable), nor able to be made immune/inviolable-to-attack by means of bail pledges, unless the last ounce (of the <fjörbaugr> fine) is paid in the court of confiscation"

<helga> "to make sacrosanct/inviolable (helgr)". Without such protection, he'd be an outlaw and so fair game to attack, with no legal repercussions for anyone who injured or killed him.