A week ago I was in an Jewish, AntiChristian chatroom. The Jews in the room were discussing their rejection on Christianity and Jesus Christ. One of their claims was Christians corrupted and mistranslated Zechariah 9:9, he told a Protestant that his version was corrupted and he cannot legitimately use the verse.
He claimed Zechariah 9:9 does not mention salvation in regards to Messiah (that the Messiah would bring salvation), saying there's no referance to it at all in the verse. Here is his translation from the chabad website (which he used despite not being a Karaite Jew).
Be exceedingly happy, O daughter of Zion; Shout, O daughter of Jerusalem. Behold! Your king shall come to you. He is just and victorious; humble, and riding a donkey and a foal, the offspring of [one of] she-donkeys.-Zechariah 9:9
As we can see this Jewish translation says "he is just and victorious" whereas virtually all "Christian" translations say "just and being salvation" or something along those lines. Only a few "Christian" translations deviate and agree with the Chabad translation above. Anyway, he insisted the Chabad translation is the best and the Hebrew word did not mean salvation since it is translated that way.
Anyway, I looked up the Hebrew word. Here is the verse in Hebrew according to the Masoretic Text, the "He is just and victorious/salvation"-- "Tzaddik v'nosha' hu" is in Red.
גִּילִי מְאֹד בַּת-צִיּוֹן, הָרִיעִי בַּת יְרוּשָׁלִַם, הִנֵּה מַלְכֵּךְ יָבוֹא לָךְ, צַדִּיק וְנוֹשָׁע הוּא; עָנִי וְרֹכֵב עַל-חֲמוֹר, וְעַל-עַיִר בֶּן-אֲתֹנוֹת
The word in contention here is וְנוֹשָׁע "v'nosha'" the "v" or "vav" simply is the "and," so the issue here is נוֹשָׁע nosha'. The word appears two other times in Hebrew bible with the same spelling:
Happy art thou, O Israel, who is like unto thee? a people saved [נוֹשַׁע] by the LORD, the shield of thy help, and that is the sword of thy excellency! And thine enemies shall dwindle away before thee; and thou shalt tread upon their high places.--Deuteronomy 33:29
O Israel, that art saved [נוֹשַׁע] by the LORD with an everlasting salvation; ye shall not be ashamed nor confounded world without end.--Isaiah 45:17
As we can see the word is being used in connection with salvation and Isaiah 45:17 even attached it with the ordinary with associated with salvation תְּשׁוּעַת
Even the Chabad translation of Deuteronomy 33:29 and Isaiah 45:17 use the word salvation for Nosha':
Fortunate are you, O Israel! Who is like you, O people whose salvation is through the Lord, the Shield Who helps you, your majestic Sword! Your enemies will lie to you, but you will tread upon their heights."--Deuteronomy 33:29 chabad.org
Israel shall be saved by the Lord [with] an everlasting salvation; you shall neither be ashamed nor disgraced to all eternity.--Isaiah 45:17 chabad.org
So, yes Zechariah 9:9 does mention the King as having salvation, but it seems that He is the recipient of it, meaning He is saved. Perhaps, this should reflect Christ's human nature. After all, having salvation does not necessarily imply a person lacked it at one point. I will look for a better explanation for this verse at a later time.
Anyway, it seems both the Missionary and the counter missionary were wrong about Zechariah 9:9.