You may like to differentiate types of prepositions in the examples you are looking at.
davidmccollough wrote:Does the non-repetition of a preposition followed by two nouns joined by καί require that the two nouns form a hendiadys? I am looking at John 3:5 γεννηθῇ ἐξ ὕδατος καὶ πνεύματος.
Some verbs are used with a particular preposition out of habit. This example that you've given seems one where the preposition is frequently associated with the verb to give the name of the mother. That would, most probably, be the basic construction of that verb. ἐκ with things other than mothers would be an extended (metaphorical
- I hate to use that word in relation to spiritual things) usage.
There are other types of prepositions that could be used, that would be used to give a new variation in meaning, but not one that is commonly used with a particular verb. Look, for example, at
Galatians 4:23 wrote:Ἀλλ’ ὁ μὲν ἐκ τῆς παιδίσκης κατὰ σάρκα γεγέννηται, ὁ δὲ ἐκ τῆς ἐλευθέρας διὰ τῆς ἐπαγγελίας.
The ἐκ is used in its grammatically natural way, to express the mother. The other two prepositions are used incidently as adverbial phrases to make points that are only relevent in this discussion in Galatians and are not going to be expected to be used with this verb.
The difference in types of prepositions - regularly occuring and incidental - is a good thing to make when you are looking at them. And for my opinion about THIS
verb, I guess it would be too strange to have ἐκ twice whether or not it was referring to separated or togethered things metaphorically (I hate the adverb of that word here too), so not much relevence could be drawn from it only occuring once with two nouns.