Generation of Moshiach is Moshiach's Donkey

The donkey is unique in the Torah. It is an impure animal lacking both external signs of purity (split hooves and chewing of the cud). The donkey in Hebrew is חמור (chamor) which is the word for materiality, even more coarse than simple "physicality".

Yet the donkey contains a hidden level of kedusha: its first born must be redeemed from the Kohen. And the donkey is mentioned in association with the greatest tzaddikim: Avraham saddled his donkey to go to the akeida; Moshe placed his wife and children on a donkey; and Moshiach, says the novi Zecharia, will appear riding on a donkey (according to chazal, the same donkey as Avraham and Moshe).

The Tikkunei Zohar (Tikkun 60) states that Moshiach's donkey, as the novi Zecharia says (9:9) "a poor man riding on a donkey" represents this state of concealed kedusha. טב מלגאו ולבושא דיליה ביש דא איהו עני ורוכב על חמור Good on the inside, but its external appearance is bad. The generation of Moshiach--neshomas on the cusp of complete refinement dressed in "filthy garments".

Perhaps this helps explain Sotah 47a, which describes the period of Ikveisa d'Meshicha (the footsteps of Moshiach) as האמת תהא נעדרת "truth will be missing". The true purity of the neshomas of this generation concealed behind outer layers of ignorance and indifference, arrogance and antagonism. But one who heeds the advice of the Alter Rebbe in Tanya perek 32--to make the body secondary and to focus on the neshoma inside--the truth will not be missing, in the way that the Torah recognizes the hidden kedusha of the first born donkey.