In Catholic liturgy, there is this ubiquitous expression used to join or precede important prayers where the priest salutes the assembly by wishing (or so I think) that the Lord be with them:
Dominus vobiscum.
(To which people respond Et cum spiritu tuo.)
Note that the verb to be is omitted. Most translations that I know translate the omitted verb as subjunctive (en: The Lord be with you, it: Il Signore sia con voi, es: El Señor esté con vosotros/ustedes). However a few translations –and some priests–, prefer to translate it as indicative (The Lord is with you, etc.). I think this is well intentioned (to assure the other party that it is not only a wish), but goes against [liturgy|the lex orandi|the intention of the text]... Or does it?
The only argument that I have goes in the lines of this is how it's officially translated. So my question be:
What are the substantial reasons for/against the subjunctive reading of Dominus vobiscum?
Since this is a language forum, I don't expect a purely theological answer, but I'd love one that links both the historic and/or linguistic aspects involved to the theological.
Update:
Maybe I should have thought of this before but... I looked up and found that the expression (the Lord be with you) is present in most early local church liturgies as attested by Church Fathers, hence it is generally agreed to have been used since Apostolic times. It is present in the Old Testament, most explicitly as an isolate salutation in Ruth 2:4, and —less isolate— in Samuel 17:37.
So there is an important clue to the answer in whether and why should these passages (in the Hebrew Bible and in the Septuagint) be unambiguously translated as subjunctive. (Together with other historic translations in or of early liturgy).