A direct translation could be "Look here on my arm" with the meaning of "Look here in my arms". Come to think of it when carrying a baby one arm is used for support therefore the direct translation is anatomically correct
Many thanks - I just wondered if we could take "Vezi aici pe braţul meu" as "See my arm" i.e. "Behold my arm / Look at my arm" (and then you'll see who is on it).
But I guess that doesn't work in Romanian.
I suppose forms like "behold my arm" can work, but I still feel I'm not getting your question, even if I take it as a poetic license.
The Christmas carol we're commenting on is deeply rooted in folklore and for reasons dealing with rythm and rhyme the boundaries of the literary language are being pushed. In Romanian we use the expression "a duce/ține în brațe" for to carry/hold in one's arms which probably has been modified into "to carry in (on, in this case) one arm" where the singular form for the possesive pronoun "meu" rhymes with Dumnezeu.
'I' ve brought God to you/in my arms for you'.
First, I believe it's 'in' for beholding, not 'on'. Also, 'see/look' is for 'ringing a bell' to the Saint Holidays. It's more like dearly widening both arms toward the interlocutor with an open heart where God sits in His rightful place - a way of welcoming the dear ones.