Well, first of all, the Messiah, according to Judaism, cannot return because he hasn't shown up yet. As for when he does show up, that's a very complicated answer. Most of that answer is located within the book of Isaiah although requirements are mentioned in other books as well. The textual requirements are: The Sanhedrin will be re-established (Isaiah 1:26) Once he is King, leaders of other nations will look to him for guidance. (Isaiah 2:4) The whole world will worship the One God of Israel (Isaiah 2:17) He will be descended from King David (Isaiah 11:1) via King Solomon (1 Chron. 22:8-10) The Moshiach will be a man of this world, an observant Jew with "fear of God" (Isaiah 11:2) Evil and tyranny will not be able to stand before his leadership (Isaiah 11:4) Knowledge of God will fill the world (Isaiah 11:9) He will include and attract all cultures and nations (Isaiah 11:10) All Jews will have returned to their homeland (Isaiah 11:12) He will swallow up death forever (Isaiah 25:8) There will be no more hunger or illness, and death will cease (Isaiah 25:8) All of the dead will rise again (Isaiah 26:19) The Jewish people will experience eternal joy and gladness (Isaiah 51:11) He will be a messenger of peace (Isaiah 52:7) Nations will end up recognizing the wrongs they did Israel (Isaiah 52:13-53:5) For My House shall be called a house of prayer for all the nations (Isaiah 56:3-7) The peoples of the world will turn to the Jews for spiritual guidance (Zechariah 8:23) The ruined cities of Israel will be restored (Ezekiel 16:55) Weapons of war will be destroyed (Ezekiel 39:9) The Temple will be rebuilt (Ezekiel 40) resuming many of the suspended mitzvos He will then perfect the entire world to serve God together, as it is written (Zephaniah 3:9) Jews will know the Torah without Study (Jeremiah 31:33) He will give you all the desires of your heart (Psalms 37:4) He will take the barren land and make it abundant and fruitful (Isaiah 51:3, Amos 9:13-15, Ezekiel 36:29-30, Isaiah 11:6-9)

As Jews, we don't believe that the Messiah will return, but that he will arrive to "save the world". Maimonides, Judaism's legal authority on the matter, identifies the following "signs" (Maimonides, Mishneh Torah, Laws of Kings Chapter 11): He will have to be a direct descendant of King David. He will be as knowledgable of Torah as King David had been and will have to observe Jewish law to the highest level of observance. He will encourage Jews throughout the world to observe traditional Jewish practice. When he succeeds in the above and brings all Jews back to Israel and rebuilds the Temple in Jerusalem, we will know he is the Messiah.

My friend. Don't believe in the supposed sacred scriptures. They are fictions. The Judaism and the Christianity are masonic religious egyptian sect that occult the truth in name of who divine entity the Messiah of Jews will make act of presence on Earth. They occult the Messiah will come in name of the Constructor of Great Pyramid, the so mentioned Biblical Pharaoh.