Can anyone help me with this riddle? It's from Hervarar saga. It's
the last part that's puzzling me: en þess fegri er færa of sér (I
believe the 'at' has been added by the editor). I'm just not sure
how this sentence works.

37. Meyjar ek sá Maidens I saw
moldu líkar, [much] like soil,
váru þeim at beðjum björg, boulders were beds to them;
svartar ok sámar sable and swarthy
í sólviðri, in sunny weather
en þess [at] fegri, but.....fairer
er færa of sér. ........themselves?

http://www.hi.is/~eybjorn/ugm/skindex/hgat.html

The answer: Góð er gáta þín. Þat eru glæðr fölnaðar á arni "Your
riddle is good. Those are embers [gledes] faded on the hearth."
(It's "faded" rather than "become lighter" in the sense of brighter,
isn't it? Fritzner has the word in a quote associated with
fölskaðr "turned to ash".)

Llama Nom

PS.
Some pictures of hearths which explain the reference to rocks (extra
cryptic because it might also suggest cliffs):

http://www.warehamforge.ca/vtakit.jpg
http://www.viking.ucla.edu/hrolf/hallin.html
http://www.bow.k12.nh.us/CyberBUS/vikings/viking.htm
http://members.fortunecity.com/showlett/sitebuildercontent/sitebuilde
rpictures/viking_house_new.jpg
http://www.lore-and-saga.co.uk/html/vikings.html