Hebrews 1:1
God, having in the past spoken to the fathers through the prophets at many times and in various ways,

 Hebrews 1:2
has at the end of these days spoken to us by his Son, whom he appointed heir of all things, through whom also he made the worlds.

Hebrews 1:3
His Son is the radiance of his glory, the very image of his substance, and upholding all things by the word of his power, when he had by himself made purification for our sins, sat down on the right hand of the Majesty on high;

The phrase “radiance of His glory” in Hebrew is “zohar kvodo.” Interestingly, there was an Ashkenazi commentary on the names of Metatron,

“Ruach pisqonit [=930] is the numerical equivalent of [the expression] Yah Yah Demut Demut [=930], for he [Metatron] had two images [demuyot], at first the image of a man and in the end the image of an angel. Ruach pisqonit is equal numerically to [the expression] ke-rl’w elev ribbo parsa [=930], for this is the measure of the stature (shi’ur haqomah). This is to inform you that the Holy One, blessed be He, has no measurement, and He has no boundary or set limit…and no eye has ever seen Him. Thus, when He selects a prophet to worship Him, he sees the splendor of His glory (zohar kevodo) on the throne in this measure.”
MSS Cambridge Heb. Add. 405, fol 302b; Oxford-Bodeleian 2286, fol. 156a; Moscoq Guenzberg 90, fol 127a; New York – JTSA Mic 2206, fol 11a, cited in Through a Speculum that Shines, Elliot R. Wolfson, Princeton University Press, pg. 223

 Hebrews 1:4
having become so much better than the angels, as he has inherited a more excellent name than they have.

 Hebrews 1:5
For to which of the angels did he say at any time, “You are my Son. Today have I become your father? and again, I will be to him a Father, and he will be to me a Son?”

Hebrews 1:6
Again, when he brings in the firstborn into the world he says, “Let all the angels of God worship him.”

 Hebrews 1:7
Of the angels he says, “Who makes his angels winds, and his servants a flame of fire.”

“He makes his messengers winds; his servants flames of fire.”
Psalms 104:4

Hebrews 1:8
But of the Son he says, “Your throne, O God, is forever and ever. The scepter of uprightness is the scepter of your Kingdom.

Hebrews 1:9
You have loved righteousness, and hated iniquity; therefore God, your God, has anointed you with the oil of gladness above your fellows.

Hebrews 1:10
And, You, Lord, in the beginning, laid the foundation of the earth. The heavens are the works of your hands.

 Hebrews 1:11
They will perish, but you continue. They all will grow old like a garment does.

 Hebrews 1:12
As a mantle, you will roll them up, and they will be changed; but you are the same. Your years will not fail.

Hebrews 1:13
But which of the angels has he told at any time, “Sit at my right hand, until I make your enemies the footstool of your feet?”

“HaShem says to my Lord, ‘Sit at my right hand, until I make your enemies your footstool for your feet.”
Psalms 110:1


Some interpret this passage as referring to Abraham,

R. Hana b. Liwai said: Shem, [Noah’s] eldest son, said to Eliezer [Abraham’s servant], ‘When the kings of the east and west attacked you, what did you do?’ – He replied, ‘The Holy One, blessed be He, took Abraham and placed him at His right hand, and they [God and Abraham] threw dust which turned to swords and chaff which turned to arrows, as it is written, A Psalm of David. The Lord said unto my master, Sit thou at my right hand, until I make thine enemies thy footstool.”
Sanhedrin 108b, Soncino Press Edition

The Midrash Rabbah says,

R. Ishmael and R. Akiba [reasoned as follows]. R. Ishmael said: Abraham was a High Priest, as it says, The Lord hath sworn, and will not repent: Thou art a priest for ever after the manner of Melchizedek (Ps. CX, 4).
Genesis Rabbah 46:5, Soncino Press Editon, Cf. Gen. Rabbah 55:6, 55:7, Lev. Rabbah 25:6, Deut. Rabbah 2:7

One thing we know for sure, is that whoever the speaker is in this psalm, the second “Lord” is greater than the speaker. While the above passages speak of Abraham as the one at God’s Right hand, the Midrash on Psalms places the Messiah there,

R. Yudan said in the name of R. Hama: In the time-to-come, when the Holy One, blessed be He, seats the lord Messiah at His right hand, as is said The Lord saith unto my lord: “Sit thou at My right hand” (Ps. 110:1), and seats Abraham at His left, Abraham’s face will pale, and he will say to the Lord: “My son’s son sits at the right, and I at the left!” Thereupon the Holy One, blessed be He, will comfort Abraham, saying: “Thy son’s son is at My right, but I, in a manner of speaking, am at thy right”: The Lord [is] at thy right hand (Ps. 110:5).
Midrash Tehillim 18.29, translated by William G. Braude, Yale University Press Edition, pg. 261

Another Midrash,

[God says:] “Ephraim, My firstborn, you sit on My right until I subdue the army of the hosts of God and Magog, your enemies, under your footstool . . .”
Mid. Alpha Betot, 2:438-42

The Rashbi is attributed as saying

” . . .the Holy One, blessed be He, will fight for Israel and will say to the Messiah : “Sit at my right.” And the Messiah will say to Israel:”Gather together and stand and see the salvation of the Lord.” And instantly the Holy One, blessed be He, will go forth and fight against them . . .May that time and that period be near!”
T’fillat R’ Shimon ben Yochai, BhM 4:124-26

The incredibly fascinating book by R’ Hillel Shklover, the disciple of the Vilna Gaon, entitled Kol HaTor (The Voice of the Turtledove), makes this amazing statement,

 יָדִין בַּ֭גֹּויִם מָלֵא גְוִיֹּות

He will judge the nations filled with corpses (Psalm 110:6) – The entire Psalm, beginning with “Sit on my right” was said about Mashiach ben Yosef, whose name is hinted at in the initial letters  יָדִ֣ין בַּ֭גֹּויִם מָלֵ֣א גְוִיֹּ֑ות going from left to right. . .”
Kol HaTor 2.61, translated by Rabbi Yechiel Bar Lev and K. Skaist, YedidNefesh.com

Indeed, the Pharisees did have a great depth of knowledge about the Tanakh:

“These are the two anointed ones, that stand by the Lord of the whole earth (Zech. 4:14). This is a reference to Aaron and the Messiah, but I cannot tell which is the more beloved. However, from the verse, The Lord hath sworn and will not repent: Thou art a priest for ever after the manner of Mechizedek (Psalm 110:4), one can tell that the Messianic King is more beloved that the righteous priest.”
The Fathers According to Rabbi Nathan, Translated by Judah Goldin, Chapter 34, Yale University Press, pg. 137-138.
Footnote:This psalm has been taken to refer to the Messiah. Cf. Epistle to the Hebrews, Chs 5-7

 Hebrews 1:14
Aren’t they all serving spirits, sent out to do service for the sake of those who will inherit salvation?