I'm not sure I have an ~answer~ for you, but I'd like to address a number of the things in this post, in reverse order. (By way of complete disclosure, I'm an author of a self-deleted answer on that question.)
We should also note that there was a lot going on with the post in the last day. Edits, comments, answers coming and going, responses to comments, upvotes and downvotes, and now a meta and a content-dispute lock. It behooves readers to sort through as much of that on their own as they can before reading my interpretation of things. And I hope it wasn't too disorienting for you and apologize to the extent that I compounded any of that.
So, 43 upvoters who think this answer was useful are wrong, because one person says that it was a bad answer (and this person is right for unknown reason), that also means that "the voting system is breaking down", and this is also an evidence that the question itself should be closed. For me, this logic is at least strange.
There is some strange logic here, but I think it's strange in the Stack-sense, not that the commenter in question is guilty of acting unreasonably. First off, the commenter was not the only person saying that it was a bad answer, there are other downvotes and a number of high-rep commenters (including me, disclosure again) had mentioned the paucity of evidence the accepted answer used in presenting how they know that biblical account has any bearing on the spell in question.
Now we get to a sticky bit: for some part of the question's history it boiled down to "why/how did this spell/concept of clerics creating water come into D&D" but for some other part (including now) it boils down to "what are some examples of magic creating water?" I'm going to call those questions A and B, respectively, because that reflects the order I saw them in.
Question A: why/how did this spell/concept of clerics creating water come into D&D? The upvoted-accepted answer is a bad answer to question A because the answer in no way describes how one could know that an early D&D author had the quoted passage in mind when making up the clerical spell list. Since there's no support for the (implied) answer "they were thinking about Moses drawing water from a stone" it should be downvoted. I'd considered putting a post notice asking for support, but since I was (briefly) another answer-author to question A I recused myself.
This, then, is the evidence that the voting system is breaking down: a question hit the HNQ, got a(n objectively) bad answer, but is getting lots of upvotes.
And that implicates the bit of logic that may seem strange: their comment about answers being evidence of the question's quality. This is a point that many people (including me, years ago) find strange: answers can tell us what's actually in the question.
Often when questions are near a boundary of topicality it's hard to see whether they are clearly on- or off-topic. (And designer intent questions--close to question A but not quite the same--have recently been discussed a few times in this light.) In those cases many people will sit back and let the answers help guide one's evaluation of the question. This seems strange, asinine, even wrong-headed to some people. But the value in it is that any question can reasonably be read many ways by different readers; answers can help one appreciate what is actually in a question beyond that subset one read themself.
Question B: what are some examples of magic creating water? The upvoted answer is a fine answer to question B, but the question is bad: it's a list-question. (Note that "list question" is a bit of a term of art in Stack-world. Not all questions whose answers are lists are "list questions," and one should read further in the meta tag for some discussion. Are list/collection questions on topic? from the faq is a good place to start.)
For me, if you think the question is too broad, it is fair either edit the question to narrow it down, or vote to close it. When you edit the question (under the pretense of making it "accurately reflect what you want") and then close it because now it is clearly "too broad" in its current state — that doesn't seem right. I didn't want my question to be closed. I wanted it to be improved and salvaged.
These are not mutually exclusive actions, nor should they be. The charitable interpretation is that one user saw (a) a title that didn't seem to reflect well the content of a post and (b) a question that should be closed. They acted to address both of those things. Based on their comments on your question, on my interactions with them in chat over the last year, and on observations of their activity around the site I, personally, have no reason to doubt they are acting in good faith rather than "play[ing] this 'find a weak spot and close the question' game." See also Should we be answering the question, or the question posed in the description?
I think such "trivia" questions actually can be useful. Answers to these "Where did feature X came from" questions help players to get inspiration from history and/or pop culture and find ways to role-play their characters.
What can I do, are there ways to salvage the question?
I agree that trivia questions are great for world- and adventure-building and roleplaying inspiration. They're sometimes great Stack questions. (Sooooo many of our questions are utter trivialities!) But "what magical water-creating predated D&D" is just as broad as "what would be some interesting enemies for my level 1 party?"
Lastly, I'll say that I think "salvage the question" isn't a goal one should pursue. Your first stab at this didn't go well and that's fine. If you want to post anew "where did the D&D idea of clerics creating water come from" I think that'd be fine. (Note that this is not a unanimous opinion; see Kryan's comment on his answer for an opposing and reasonable viewpoint.) It may get a good answer along the lines HeyICanChan described, or it may draw dreck and we have to moderate those answers. But that's not your fault.