Thanks. Hume’s response seems clear: if miracles were common, they would amount to natural regularities, since we’d perceive and explain them in the same way we do with nature. We’d perceive regular concatenations of events and by habit we’d posit necessary connections and explain the patterns with generalizations and models (natural laws).
If the Christian’s mountain of miracles is supposed to be in Heaven, that’s an appeal to what’s not in evidence, which begs the question. If that mountain is in nature, it becomes just more nature, as far as we could tell with empirical justification (with appeals to sense data).
If, however, the mountain of miracles is meant to be a philosophical interpretation of nature itself as being re-enchanted, I’d have some sympathy with that, as my latest Medium article should make clear.