This phrase can be found in Tobit 5:6, in the Vulgata:
Et ignorans quod angelus Dei esset, salutavit eum, et dixit : Unde te habemus, bone juvenis?
The accompanying English translation reads:
And not knowing that he was an angel of God, he saluted him, and said: From whence art thou, good young man?
It seems to me the English translation conveys the same intended meaning, and it is perhaps simpler. But would the literal translation of Unde te habemus be "From where do we have you?" Is this use of habeo common? Or is it purely a Vulgata thing? Actually, this is the first time I recall encountering such expression.