The oldest apocalypse in which the conception of a preexistent heavenly Messiah is met with is the Messiological section of the Book of Enoch (xxxvii.-lxxi.) of the first century B.C. The Messiah is called “the Son of Man,” and is described as an angelic being, his countenance resembling a man’s, and as occupying a seat in heaven beside the Ancient of Days (xlvi. 1), or, as it is expressed in ch. xxxix. 7, “under the wings of the Lord of spirits.” In ch. xlviii. 3, 6, xlix. 2b it is stated that “His name was called before the Lord of spirits before the sun and the signs of the zodiac were created, and before the stars of heaven were made”; that “He was chosen and hidden with God before the world was created, and will remain in His presence forevermore” (comp. also lxii. 6); and that “His glory will last from eternity unto eternity and his might from generation unto generation” (that “his name” in xlviii. 3 means really “son of man” is evident from verse 6; comp. the similar use of “Shem Yhwh” for “Yhwh” in Isa. xxx. 27).
He is represented as the embodiment of justice and wisdom and as the medium of all God’s revelations to men (xlvi. 3; xlix. 1, 2a, 3). At the end of time the Lord will reveal him to the world and will place him on the throne of His glory in order that he may judge all creatures in accordance with the end to which God had chosen him from the beginning.
When he rises for the judgment all the world will fall down before him, and adore and extol him, and give praise to the Lord of spirits. The angels in heaven also, and the elect in the Garden of Life, will join in his praise and will glorify the Lord. “He will judge all hidden things, and no one will be able to make vain excuses to him”; he will judge also Azazel [a fallen angel that appears in 1 Enoch], with all his associates and all his hosts. The wicked ones of the earth, especially all kings and potentates, he will give over to damnation, but for the just and chosen ones he will prepare eternal bliss, and he will dwell in their midst for all eternity (xlv. 3, 4; xlvi. 4-6; xlviii. 4-10; xlix. 4; li. 3; lv. 4; lxi. 7-lxii. 14).
— Jewish Encyclopedia, “Messiah” (via jedimasterkirito)