The Jewish Scholar Maimonides Explains the Appearance of King Mashiach (Hazrat Mahdi [pbuh])

In the 12th century, Musa Ibn Maymun (Rabbi Mosheh Ben Maimon; Maimonides), a preeminent medieval Torah scholar wrote in a letter to Yemen:

What is to be the manner of Messiah's advent, and where will be the place of his appearance?

And Isaiah speaks similarly of the time when he will appear… He came up as a sucker before him, and as a root out of the dry earth, etc. But the unique phenomenon attending his manifestation is, that all the kings of the earth will be thrown into terror at the fame of him. Their kingdoms will be in consternation, and they themselves will be devising whether to oppose him with arms, or to adopt some different course, confessing, in fact, their inability to contend with him or ignore his presence, and so confounded at the wonders which they will see him work, that they will lay their hands upon their mouth; in the words of Isaiah, when describing the manner in which the kings will hearken to him, "At him kings will shut their mouth; for that which had not been told them have they seen, and that which they had not heard they have perceived."

Reference: The Suffering Servant of Isaiah, Driver and Neubauer vol. 1, p. 322. [Abraham S. Halkin, ed., Igeret Teman (New York: American Academy for Jewish Research, 1952)]