Á Sprengisandi (Ríðum, ríðum rekum yfir sandinn)

I put ‘workhorse’ because that’s what my dictionary said for ‘klár’, but yeah, I did miss that ‘vænn’ was in the superlative form (best, not good).
The word ‘því’ confuses the hell out of me, so I’m never very good at sentences with it in. It seems to have so many different uses. Now I think about it, I suppose it couldn’t be ‘it’, because andi is masculine and also that form of it is not in the nominative case. Has anyone ever told you your language is beautiful, but very confusing?

Thanks very much for correcting me, I never know whether I’ve got something quite right. But the 3rd line is still confusing me. I thought ‘margur’ was ‘many’, as you said, but then ‘andi’ was in the singular form and so was the verb ‘vera’, so I supposed ‘margur’ had a secondary use as an intensifying adjective, and just put ‘very’. How can there be many of only one thing?

Apologies for mistakes in spelling Ódáðahraun and Kiðagil, but these are probably the least of my mistakes!

We ride, we ride, we drive over the sand
The twilight is sinking at Herðubreið
The elf-queen is harnessing her horse
It is not good to cross her path,
I wanted to give my good workhorse
To be arrived in Kiðagill
I wanted to give my good workhorse
To be arrived in Kiðagill

Shh! Shh! Shh! Shh! The vixen sang in the wood,
She wants blood to wet her dry mouth,
Or someone was also calling,
A strangely thick male voice,
Outlaws in Óðáðahraun
Are perhaps gathering sheep in secret.
Outlaws in Óðáðahraun
Are perhaps gathering sheep in secret.

Here is my very amateur attempt at a translation:

We ride, we ride, we drive over the sand,
The sun slips behind Arnarfell (Eagle’s Mountain)
Here at large is a very dirty spirit
Out it goes casting shadows on the glacier.
The Lord leads my horse,
Far will be the rest of the journey.
The Lord leads my horse,
Far will be the rest of the journey.