What did the butler and the baker mean when they said to Yosef "There is no interpreter"? Did they really expect to find an interpreter in prison?
Ramban #1: They actually sent a request to various magicians to interpret their dreams.
Ramban #2 and Seforno: What they meant was that nobody in the world could possibly interpret them. 1
Ha'Emek Davar: Indeed, they meant that since they are imprisoned, strangers may not enter, therefore there is no interpreter.
If each dreamed the interpretation of the other's dream (refer to 40:5:1:2), they could have interpreted for each other! Granted, the butler did not want to give the morbid interpretation of the baker's dream. However, the baker could have interpreted the butler's dream! Perhaps he did not want to, due to an evil heart. In Selichos for Asarah b'Teves (Nusach Ashkenaz), in the Pizmon, we ask that our enemies receive what they deserve, like he did! (PF) Alternatively, the baker did not realize that what he saw was the interpretation of the butler's dream. (EC)
Why did Yosef say that interpretations lie in the Hands of Hashem?
Ramban #1 (citing the Ibn Ezra): Hashem alone interprets. Consequently, in the event that he (Yosef) interprets their dream for better or for worse, the interpretation has nothing to do with him. 1
Ramban #2: Since Hashem is the Master of interpretations, He is able to pass on the interpretation of a dream to whoever He wishes - and would therefore pass it on to Yosef, should He so desire.
Seforno: Man's ability to interpret dreams stems from the fact that he is made in the Image of G-d (b'Tzelem Elokim), in which case it was possible that he, Yosef, in spite of his current situation, would be able to interpret their dreams. 2
Ohr ha'Chayim #1: Do not think that I aggrandize myself through interpreting your dream. Hashem has many interpreters (people to whom He tells interpretations); I am one of them.
Ohr ha'Chayim #2: There can be many interpretations of a dream, and all of them are true (Brachos 55b).
Malbim: Dreams inform about Divine decrees. Hashem would not tell you if He did not prepare the interpreter. If not, the 'informing' was for nothing!
Malbim citing a Midrash: He attributed the greatness to its owner. Dreams are not from the Ma'arachah (arrangement of stars) or from the power of imagination 3 , rather, an influence from Hashem. So He will put an influence on me to tell you the interpretation!
Ha'Emek Davar: Other Chachmos depend only on intellect and study. Dream interpretation is a Segulah of the Nefesh; it pertains only to Hashem, who 'appears' on a Nefesh with this Segulah. I have it, even though I did not learn much in academies of Chachmah.
He said this so that, should the interpretation turn out to be bad one, they would not hold it against him, or to encourage them to tell him their dreams without embarrassment.
And their claim that nobody could interpret their dreams was therefore not justified.
Why did he say "Na"?
Ohr ha'Chayim #1: Tell it to me now. The interpretation must come the same day. We find that we fast due to a dream only that day, even if it is Shabbos (Shabbos 11a).
Ohr ha'Chayim #2: Tell it to me now, before you tell others, lest another interpretation be fulfilled. Even though many different interpretations of a dream can be fulfilled (Brachos 55b), this is only if they do not contradict each other.