I have been told that the greeting ave or have is of Punic origin and not an imperative of avere. If so, how do I use this word to greet several people? Is it in the same form, is it pluralized to (h)avete as if it was an imperative, is it something else, or is it not used at all in the plural? With a clear imperative like salve I can go salvete in the plural, but I am not sure about ave.
If at all possible, I am looking for attested use in classical Latin or as close to it as possible.
While it might be interesting how the word worked in the Punic language, it is somewhat irrelevant here. I am after the usage in classical Latin, and it need not correspond to the structures in the language of origin. If it turns out that ave is to be understood as an imperative, then avete is expected and should be attested.