Moshiach: Hidden in Gan Eden

"Moshiach will be taken from the world to Gan Eden and from there he will be revealed."

Maharsha, Chiddushei Agados, Sanhedrin 98b

"Moshiach does not die, but rather he lives in the lower Gan Eden prepared for the salvation of Israel, and he has no permission to depart from there until they give him permission from Above. He has no permission to ascend to the upper Gan Eden, the place of the neshoma, nor to descend to the place of bodies."

Ohr Hachama on the Zohar, V'yakhel 212b