The use of a varied vocabulary is no proof of a different authorship. It is necessitated by the changes of subject.
burden = Divine declaration. Hebrew. massa' . Compare Isaiah 13:1 .Nahum 1:1 .
of = that is to say. Genitive of Apposition. See App-17 .
the LORD. Hebrew. Jehovah . App-4 .
in: or, on: i.e. resting on.
Hadrach. A country in the neighborhood of Damascus and Hamath (Zechariah 9:2 ) &c., mentioned in the Assyrian Inscriptions, with the 'arka of Genesis 10:17 .
the rest thereof = its resting place: i.e. the burden will rest upon it.

Hamath. Now Hama,
shall border thereby = [which] bordereth thereon: i.e. on the land of Hadrach.
though = because.

Tyrus. strong hold. Note the Figure of speech Paronomasia . Hebrew. zor mazor , which cannot be reproduced in English.
as = like.

Behold. Figure of speech Asterismos. App-6 .
the Lord* . One of 134 places where the Sopherim say they altered "Jehovah" to "Adonai". App-32 and compare App-4 .
cast her out = dispossess her.

Ashkelon. Now 'Askalan.
see. fear. Note the Figure of speech Paronomasia ( App-6 ). Hebrew. tera. vetira . May be Englished by "shall gaze . and be amazed (or be dazed) ": or "shall peer and fear".

bastard = half-breed, or mongrel.
dwell = sit [as king].
Ashdod. Now Esdud.

blood. Hebrew bloods. Put by Figure of speech Metonymy (of Adjunct), App-6 , for the sacrifices (which were, of course, eaten).
abominations: i.e. the idolatrous sacrifices.
he that remaineth: i.e. the remnant of them.
even be = he also.
shall be for. Supply the Ellipsis thus: "[shall be subject unto]. "
God. Hebrew. Elohim . App-4 .
governor = chieftain, or duke.
Ekron. Put by Figure of speech Synecdoche (of the Part), App-6 , for Philistines.
Jebusite. Put by Figure of speech Metonymy (of the Adjunct), App-6 , for bondservant. (1 Kings 9:20 , 1 Kings 9:21 .Isaiah 11:14 .)

because of = against.
passeth by. returneth : i.e. marcheth to and fro. and: or, so that.
oppressor. Hebrew. nagas = to press hard, as a task-master (Exodus 5:6 ), or as a foreign oppressor (Isaiah 9:4 ; Isaiah 14:2 , Isaiah 14:4 ), or as an exactor (2 Kings 23:35 ).
seen . Supply the Ellipsis: "seen [the affliction of My People] with Mine eyes".

Rejoice, &c. Figure of speech Paeenismos. App-6 . This verse foretells the first coming of Messiah, recorded in the Gospels.
cometh unto = will come unto. See note on Micah 5:2 , where we have the going forth from Bethlehem (Matthew 2:1 ). Here we have the coming unto Jerusalem (Matthew 21:5 ). Between these lay all the events which we call "the first advent'. So will it be at "the second advent" with its many events, before e. to is fulfilled. See notes on Matthew 21:1-10 , and Luke 19:25-44 ; App-107 and App-156 .
He is , &c. Note the four features of Messiah's character and condition at His first advent.
(1) just = righteous, as being justified or vindicated. Compare Isaiah 45:21 ; Isaiah 53:11 .Jeremiah 23:5 , Jeremiah 23:6 .
(2) having salvation. Hebrew. nosha is the Niphal participle, which, though it may be reflexive, is never active. He was heard and delivered (Psalms 22:20 , Psalms 22:21 .Hebrews 5:7; Hebrews 5:7 ), referring to His own sufferings and death out of (Greek. ek, App-104 .), which He was delivered (Psalms 16:10 . Acts 2:24 ), and by which He becomes the Saviour of others (Isaiah 53:8 , Isaiah 53:10 , Isaiah 53:11 ).
(3) lowly = afflicted, or oppressed. Same word (' ant; see note on "poverty", Proverbs 6:11 ) as in Psalms 22:24 .Isaiah 53:4 , Isaiah 53:7 .
(4) riding upon an ass , &c. Fulfilled (1) in Matthew 21:1-11 , and from two days afterward (2) in Mark 11:8-11 .Luke 19:36-46 . John 12:12-19 . See App-156 . A mark of His lowliness. Note the above four characteristics.

I will cut off. Septuagint reads "and He will cut off". This refers to the yet future second coming; the present dispensation ( App-71 and App-72 ) lying between Zechariah 9:9-10 .
He shall speak peace , Sc. Compare Psalms 46:9 ; Psalms 47:3 .Isaiah 2:4 ; Isaiah 9:6 , Isaiah 9:7 . Micah 5:5 .
heathen = nations.
from sea . . . to sea. Compare Psalms 72:8 .
the river : i.e. the Euphrates.

thee = thee [O Zion] (feminine; agreeing with Zion), which is also feminine in verses: Zechariah 9:9 , Zechariah 9:13 .
the blood of thy covenant : or, thy covenant of blood. Reference to Pentateuch (Exodus 24:5-8 ) Compare Hebrews 13:20 .
have sent forth = i.e. sent forth [from their captivity].
out of the pit, &c. Reference to Pentateuch (Genesis 37:24 ).

Turn = Return.
strong hold. Hebrew. bizzaron (from bazaar , to cut off) = a safe because of inaccessible place. Occurs only here.
hope = the hope: i.e. which God had given, and on which He had caused them to hope (Psalms 119:49 ).
double: i.e. a prosperity and blessing double what was possessed before.
The firstborn's share . Compare Isaiah 61:7 .

filled = grasped.
thy sons, O Greece. Septuagint reads "the sons of Greece.
Greece. Hebrew. Yavan . Compare Genesis 10:2 , Genesis 10:4 .Isaiah 66:19 . Ezekiel 27:13 .Daniel 8:21 ; Daniel 11:2 .Joel 3:6 .

His arrow. Figure of speech Anthropopatheia. App-6 .
the Lord. Hebrew. Adonai App-4 .
God. Hebrew. Jehovah .

The Lord of hosts. See note on Zechariah 1:3 .
defend. See note on Isaiah 31:5 .
devour = devour [their enemies].
subdue with sling stones: or, trample on their weapons.
and. Some codices, with three early printed editions, read this "and" in the text.
make noise = shout.
wine. Hebrew. yayin . App-27 .
filled: i.e. filled [with wine] like.
as, &c. = as the sacrificial bowls [are filled with blood, which are tossed against] the corners (or horns) of the altar.

stones = gems.
crown = diadem.
lifted up = conspicuous, or sparkling.
land = soil.

cheerful = flourish.
new wine. Hebrew. tirosh. App-27 .