I've heard from some people that one can't "choose" to dream about Elyahu HaNavi and that whenever one dreams about him it's for sure the true Eliyahu HaNavi, meaning, it was the prophet himself showing up in the dream, with a message or something.

Now, if the above is true, then whatever Eliyahu says in the dream must be necessarily true, otherwise he would be spreading lies around, no?

So, is the above true? Is there a source for that?

I've heard from some people that one can't "choose" to dream about Elyahu HaNavi and that whenever one dreams about him it's for sure the true Eliyahu HaNavi, meaning, it was the prophet himself showing up in the dream, with a message or something.

Now, if the above is true, then whatever Eliyahu says in the dream must necessarily be true, otherwise he would be spreading lies around, no?

So, is the above true? Is there a source for that?