A rough literal translation (actual Spanish speakers feel free to rip my translation up :-)

Riu, riu, chiu

The shore guard

God keep the wolf

From the Lamb.

The rabid wolf wanted to bite Him,

But almighty God knew to defend Him;

He wanted to make the man who cannot sin,

Not even Original Sin as Our Virgin did not have.

Who is this born? Born is the great king,

Christ our Father made man [lit. "wearing flesh"];

Hanos [Mankind?] redeemed by Himself made very small,

Even the infinite, is made finite.

Many prophets have prophesied it,

and in our days we have even sung it.

God made man we see on Earth

and to the man nel [?] sky to porqu'er [?] wanted to him.

I saw thousands of Garzones [people?] singing in Andavan,

Bolando [dancing?] by here, doing thousands sones [of steps?],

Giving to Men, Gloria in the Highest,

and peace on Earth since Jesus is born.

He comes to give life to the dead

and comes to heal the [sick? lame?];

[Bright?] is the light of that day;

This is the Lamb that spoke to Saint John.

Since we already have what we [desire? deserve?],

All together we will go to offer Him presents;

We will give our souls to him,

Because to make Himself one with man He came.

BB,

NightWing