Hebrews 2:2 For if the word spoken by angels was stedfast, and every transgression and disobedience received a just recompence of reward;

(How many different angels spoke the word of the LORD?

First, is the angel of the LORD, the same one, who is mentioned in all the following 9 occurrences?)

Genesis 16:9 And the angel of the LORD said unto her, Return to thy mistress, and submit thyself under her hands.

Genesis 22:11 And the angel of the LORD called unto him out of heaven, and said, Abraham, Abraham: and he said, Here am I.

Judges 2:4 And it came to pass, when the angel of the LORD spake these words unto all the children of Israel, that the people lifted up their voice, and wept.

Judges 6:12 And the angel of the LORD appeared unto him, and said unto him, The LORD is with thee, thou mighty man of valour.

Judges 13:18 And the angel of the LORD said unto him, Why askest thou thus after my name, seeing it is secret?

I Kings 19:7 And the angel of the LORD came again the second time, and touched him, and said, Arise and eat; because the journey is too great for thee.

II Kings 1:15 And the angel of the LORD said unto Elijah, Go down with him: be not afraid of him. And he arose, and went down with him unto the king.

I Chronicles 21:16 And David lifted up his eyes, and saw the angel of the LORD stand between the earth and the heaven, having a drawn sword in his hand stretched out over Jerusalem. Then David and the elders of Israel, who were clothed in sackcloth, fell upon their faces.

  18 Then the angel of the LORD commanded Gad to say to David, that David should go up, and set up an altar unto the LORD in the threshingfloor of Ornan the Jebusite.

Zechariah 3:6 And the angel of the LORD protested unto Joshua, saying,

(Also, is the angel of the LORD possibly a pre-incarnate appearance of the Son?)

(Then, who is this angel that Solomon is speaking about?)

Ecclesiastes 5:6 Suffer not thy mouth to cause thy flesh to sin; neither say thou before the angel, that it was an error: wherefore should God be angry at thy voice, and destroy the work of thine hands?

(Then, who is the angel of his presence, mentioned in Isaiah? Is he the same as the angel of the LORD?)

Isaiah 63:9 In all their affliction he was afflicted, and the angel of his presence saved them: in his love and in his pity he redeemed them; and he bare them, and carried them all the days of old.

(Then, who is the Angel, with a capital “A"?)

Genesis 48:16 The Angel which redeemed me from all evil, bless the lads; and let my name be named on them, and the name of my fathers Abraham and Isaac; and let them grow into a multitude in the midst of the earth.

Exodus 32:34 Therefore now go, lead the people unto the place of which I have spoken unto thee: behold, mine Angel shall go before thee: nevertheless in the day when I visit I will visit their sin upon them.

(Is the Angel, which redeemed Jacob, the same as he whom the LORD called, “mine Angel”?

Is he the same as the angel of the LORD? He is the same as the angel of his presence?

Are all the ones mentioned, above, referring to the same one?)

(Then there are a couple of other angels, who are named, yet who appear to not be “the" angel of the LORD.

They are also angels, and also of the LORD, but again, they are not called “the angel of the LORD”.

One of these other two named angels is Gabriel:)

Daniel 9:21 Yea, whiles I was speaking in prayer, even the man Gabriel, whom I had seen in the vision at the beginning, being caused to fly swiftly, touched me about the time of the evening oblation.

Luke 1:19 And the angel answering said unto him, I am Gabriel, that stand in the presence of God; and am sent to speak unto thee, and to shew thee these glad tidings.

  26 And in the sixth month the angel Gabriel was sent from God unto a city of Galilee, named Nazareth,

(The other of these two named angels is Michael:)

Jude 9 Yet Michael the archangel, when contending with the devil he disputed about the body of Moses, durst not bring against him a railing accusation, but said, The Lord rebuke thee.

(So, back to the first question, how many different angels spoke the word of the LORD?)