Vera Lex,
I agree with some of what you wrote -
and more importantly, I appreciate that
you invested the time to do so.
I am personally unaware of any so called
“white marriages”. Is this common in your
area?
Frankly, in Greek, I just don’t see your
interpretation of Mary’s statement. Her
words literally mean, ““since I have not
known a man”. It is more specific than
saying “I have not known a man.”
I understand, from the quotes by early Church
Fathers that it was widely taught that Mary
remained a virgin forever. This was taught
at least as early as 248 AD. I don’t know yet
of any earlier references during the intervening
247 years. If you have access to any references
during that period, I would be in your debt,
if you would post them.
Thank you again for your efforts and time.
Best,
ampu
Mary's response to Gabriel is not in the past tense, that was the point I was trying to make. "How shall this be..." (ἔσται -future tense), "since I do not know man" (γινώσκω -present tense). Literally then she is not saying that she "has not known a man" but that she "does not know man" and it is this phrase which theologians have interpreted to indicate a vow of perpetual virginity.
How is one led to such a conclusion? Crucially the first part of the angel's message regards a future event: he tells Mary that she will in the future conceive a child. (Note the angel was not at this point announcing that Mary had already conceived a child since the incarnation would only happen once Mary uttered her fiat which is recorded in verse 38 after this exchange). So the Angel is not saying in verse 31 "You are already with child", to which a bemused Mary could legitimately have asked, "How is this possible since I am a virgin?"
Instead a girl about to be married expresses confusion as to how she could possibly conceive a child in the future. Such a response would be utterly bizarre. Bizarre unless we understand Mary to be saying something different which is, "How could God wish me to have a child since I have consecrated myself to him as a virgin?".
Verse 35 then records the angel's response to Mary's legitimate question. He explains how Mary will conceive without breaking her vow of perpetual virginity.
To sum up, it makes no logical sense for Mary to respond to the angel's announcement of a future pregnancy with the statement that this is not possible because she has not yet known a man.
This in response to your post asking for any direct Scriptural justification for the doctrine of the perpertual virginity of Our Lady; about tradition and early Church documents I have nothing I can usefully add to what has already been cited.
(White marriages are not too common these days.)