“And Moshe took his wife and sons and mounted them on the donkey.”(Shemot 4:20)
Rashi makes the cryptic comment, “The donkey that Moshiach will utilize to usher in the Final Redemption.” How do we understand this strange comment of Rashi? Can a donkey live for thousands of years? The explanation is that Rashi is speaking metaphorically. Rashi means that  when G-d appointed Moshe to be the Redeemer of Israel, He set those cosmic forces in motion that will culminate and climax with the coming of Moshiach and the Final Redemption.
 
The prophet Micah said (7:15), "As in the days of your leaving Egypt, I shall show them marvelous things." His words imply that the Exodus is the precedent for the Final Redemption, as the Midrash expounds:
 
"Just as in Egypt, I shall redeem you in the future from subjugation to Edom and shall perform miracles for you, as it says, 'As in the days of your leaving Egypt, I shall display miracles' (Tanchuma, Toldot 17)."
 
Indeed, gradual, phased redemption is found already in Egypt, as in the four redemption expressions with which G-d addresses Moses:
 
"Therefore tell the Israelites that I am the L-rd. I will remove you (1) from the suffering of Egypt, and I will save you (2) from your enslavement. I will redeem you (3)  with an outstretched arm and with great punishments, and I will take you (4) to Me as a people. I will be for you a G-d" (Exodus 6:6-7).
 
This refers to four stages of redemption. The first stage constituted a lightening of their hardship, although they continued to be Pharaoh's slaves. (According to the Netziv, Rabbi Naphtali Zvi Yehuda Berlin, this occurred during the plague of the wild animals [ Arov].). The second stage constituted the total cessation of their enslavement (with the plague of hail, during which Pharaoh began to admire Israel -- Netziv). Even so, Israel were not yet free, but under the control of the Egyptian regime. With the plague of the firtborn came the third stage, in which Israel were redeemed totally, with an outstretched arm and with great punishments, and they left slavery for freedom. Yet they were still mired in the forty-nine levels of impurity like idol worshippers. Finally came the fourth stage, in which they were taken to be Hashem's people, and Hashem became their G-d.
 
Even though Israel, when redemption arrived, were not worthy of it, G-d still redeemed them, as is stated in the Midrash (Shemot Rabbah 15):
 
"G-d said, 'If I consider Israel's deeds, they will never be redeemed. Whom shall I then consider? Their holy ancestors. Through their ancestors' merit I will redeem them.'"
 
It is not just Israel's condition in the past which delays redemption, but their anticipated condition in the future as well. Therefore, before introducing the four redemption expressions, G-d says, "Therefore, tell the Israelites that I am the L-rd, " regarding which our sages commented:
 
"I know that they will ultimately rebel against Me and anger Me. Even so, I shall redeem them for the sake of My name" (Midrash Hagadol).
 
Complete redemption comes when Israel recognizes Hashem as their G-d, as occurred during "Stage Four," at the Sinai Revelation. Yet the Torah goes on and brings a fifth redemption expression: "I will bring you to the land regarding which I swore that I would give it to Abraham, Isaac and Jacob. I will give it to you as an inheritance. I am the L-rd" (Exodus 6:8). From the redemption from Egypt we learn that complete redemption consists of when Israel is free ["I will redeem you…"], and living in Eretz Yisrael ["I will bring you to the land"], and they believe in G-d and fulfill His commandments ["I will be for you a G-d"]. The Final Redemption will reach completion by a gradual process, in various stages, just like the Exodus from Egypt.