Tu Scendi Dalle Stelle (You Descend from the Stars)
https://youtube.com/watch?v=fd2SKxUs2gM

You Descend from the Stars, O King of Heaven,
And come to a cave, in the cold and frost,
And come to a cave, in the cold and frost.
O my divine Child,
I see thee here trembling;
O blessed God!
O how much did it cost thee, to have loved me!
O how much did it cost thee, to have loved me!

To thee, who art of the world, the Creator,
lack cloths and fire, O my Lord,
lack cloths and fire, O my Lord.
Dear chosen, little child,
How much this poverty
The more it enamors me,
Since love made thee, poor still,
Since love made thee, poor still. 

https://en.wikipedia.org/wiki/Tu_scendi_dalle_stelle
The chant was composed by a bishop of the area of Naples, in December 1754.
https://en.wikipedia.org/wiki/Alphonsus_Liguori
I've retranslated it to follow more closely the original text.