Moshiach hidden and revealed

The great scholar Rabbi Chiam Midini, in his work (Sdei Chemed, Peyas HaSaden, Maareches "Alef", os Eyin) elaborates on this subject, he connects the Talmudic statement in (Sanhedrin 98b) to an earliar one (San.98a) referring to the prophecy of Daniel: "If the generation is fortunate the Mashiach will come from the dead, i.e., on 'clouds of heaven,' and then everyone will accept him with no reservations. But if not he will come from the living, i.e., 'riding on a donkey."

Rashi one of the foremost expositors of Scriptures and the Talmud, in the book of Daniel (12:12) he writes: "The Mashiach will reveal himself and then be concealed… and then revealed once more, and so it says in the Midrash Ruth and the in the poems of Rabbi Eliezer HaKalir."

The Talmud says emphatically:

"Rav says that if Mashiach is among those who are living, then its Rabbeinu Kakodesh, and if he's among those who passed on, then it's Daniel."  – (Sanhedrin.98b)

As we can see the definition of Judaism is that which is written in the Torah. This possibility that Mashiach comes, and after his coming and revelation there is a interruption, and then he completes the process is actually found in a number of Torah sources.

Revealed, Concealed, Revealed Again

"My beloved is like a deer,' just as a deer is seen and revealed and is again concealed, so did the first redeemer [Moshe Rabbeinu] appear to them and was again concealed, and then revealed again. So also the future redeemer [Mashiach] will be revealed and concealed." – (Midrash Rabba Shir HaShirim 2:22, on "Domeh dodi l'tzvi")

The revelation of Mashiach and the Redemption are two separate issues. We see this from the story of Moshe Rabbeinu. Moshe's revelation was when he came and said to the Jewish people, "I'm taking you out of Galus (Exile)." When he came to Pharaoh and he said, "Let my people go," that was the revelation of the redeemer [Moshe]. The Redemption from Egypt only began later because as we know, not only didn't the Jewish people go out of exile – things actually got worse. So the fact that he was revealed as the redeemer is one thing. And then came the second stage. This is how it was with the first redemption (Egypt). The Geulah is a process. Over there, it took a few months and then he appeared again and took the Jews out of Exile, whereas now (the final Redemption) it's taking longer – much longer.

Rashi commenting on (Daniel 12:12) says, "Ashrei ha'm'chakim" (fortunate are those who will wait for Mashiach). Rashi explains this is not just talking about people in general who wait for Mashiach. Rather, fortunate are those who will wait for Mashiach after he is revealed, and then he will be hidden, then revealed again. In that in-between-time, fortunate are those who persevere in their emunah.

The Chasam Sofer, the great halachic master says in (Toras Moshe, Parsha Shmos), the fact that Moshe was gone for six months was a very big test. The same will be in the Days of Mashiach Tzidkenu, he will be concealed after he is revealed, and we will need special assistance from the Holy One, blessed be He, to stand during this great test.

This can also be found written by Rabbi Isaac Luria (the Arizal), the great kabbalist in his work (Shaar HaGilgulim, 13 and 31). He describes how Mashiach will be a human born to father and mother, who will grow up to be a great tzaddik, and he will be given the task to take the Jews out of Exile. Afterwards, like Moshe Rabbeinu who went up to the mountain for 40 days and 40 nights, and then came back. This is how Mashiach will be. When Mashiach gets here not everyone will accept him, he will disappear, then come back, take the Jews out of Exile and then everyone will accept him.