Эта запись не вполне соответствует тексту, хотя здесь мы явно имеем дело просто с разными вариантами. Выкладываю то, что я услышал:

There’s a valley in Spain called Jarama,
It’s a place that we all know so well;
And it’s there that we fought against the fascists
And we saw the peaceful valley turned to hell.

From this valley they say that we’re going;
Do not hasten to bid us adieu
Even though we lost the battle of Jarama,
We’ll set this valley free, for we threw.

We were men of the Lincoln Battalion,
Proud of the fight that we made,
We know that you people of the valley
Will remember our Lincoln Brigade.

From this valley they say we are going
But don’t hasten to bid us adieu
Even though we lost the battle of Jarama,
We’ll set this valley free, for we threw.

Единственная проблема - "for we threw", слышится четко, смысл ясен - "поклялись" - но ни в одном словаре такого смысла у throw нет...