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?
The closest I can find is the song אֵלִיָּהוּ הַנָּבִיא sung by many on Motzai Shabbat.
It can be found in most Siddurim.
The second to last verse is אַשְׁרֵי מִי שֶׁרָאָה פָנָיו בַּחֲלוֹם, אַשְׁרֵי מִי שֶׁנָּתַן לוֹ שָׁלוֹם, וְהֶחֱזִיר לוֹ שָׁלוֹם - happy is the one who sees him (Eliyahu Hanavi) in a dream, happy is one who was given Shalom (greeted) by Eliyahu Hanavi.
This makes it sound that merely seeing Eliyahu Hanavi in a dream is a big deal; and not something that simply happens as a result of thinking about him during the day (which is the cause of most dreams).
However, it doesn't talk about the veracity of any message Eliyahu Hanavi may tell you in a dream. (Nor does it mention how to identify him.)
It is a common practice in Gedolim to not immediately listen to a dream unless it repeats itself three times.
