Because of Its Bearing Upon Israel.
Israel's future blessings wait for the Return of their Messiah. When He was here before He was despised and rejected by His brethren according to the flesh, but when He comes back again to this earth they shall welcome and worship Him. That prophecy of Zechariah's which received a partial fulfillment when He was here before, is yet to receive a further and complete fulfillment, in the days of His Second Advent. This is clear from the words which immediately follow these which had reference to His entry into Jerusalem a few days before His crucifixion -- "Rejoice greatly, O daughter of Zion; shout, O daughter of Jerusalem; behold, thy King cometh unto thee: He is just, and having salvation; lowly, and riding upon an ass, and upon a colt the foal of an ass. And I will cut off the chariot from Ephraim, and the horse from Jerusalem, and the battle bow shall be cut off: and He shall speak peace unto the heathen: and His dominion shall be from sea even to sea, and from the river even to the ends of the earth" (Zech.9:9, 10). And note further the closing verses of the same chapter -- "And the Lord their God shall save them in that day as the flock of His people; for they shall be as the stones of a crown, lifted up as an ensign upon His land. For how great is His goodness, and how great is His beauty! corn shall make the young men cheerful, and new wine the maids" (vss.16, 17). The real "Triumphal Entry into Jerusalem" is yet future. Our Lord is to enter the royal city again and at the time of His return He shall enter it as King in fact and in full manifestation of that fact. Then it is that Zion's King shall come to her "having salvation," and then it is that Israel shall marvel at His grace and at His excellency; and then it will be that the daughter of Jerusalem shall be exalted and be once more owned and blessed by Jehovah. It is on the return of Christ to this earth that Israel shall enter into the enjoyment of that inheritance which was given unto their fathers, and under the reign of their Messiah shall become a blessing to all nations. Again; the Redeemer's Return is a blessed Hope.