The Colt is like the Gentiles and the Ass is like the Jews

"And they brought the colt to Jesus, and cast their garments on him; and he sat upon him" (Mark 11.7). "And they brought him to Jesus: and they cast their garments upon the colt, and they set Jesus thereon" (Luke 19.35). "And Jesus, when he had found a young ass (a young ass is a colt), sat thereon; as it is written" (John 12.14). "And brought the ass, and the colt, and put on them their clothes, and they set [him] thereon" (Matt. 21.7).

By mentioning only the colt in three of these verses is in no way precluding riding on an ass also or having the ass follow close behind. Otherwise it would say "only". And Jesus would had to have one but cheek on the ass and one but cheek on the colt. That would be funny and impossible since they are of different heights. I really don't think that is what Zech. 9.9 meant.

As He was about to enter Jerusalem, He could very well have exercised His creative power to create an ass for His ride through the city—just as He had created many living creatures during the time when, according to Genesis 1.1-2ff., He repaired the earth. And yet He took pleasure in sending His disciples to fet_ch. the ass with the colt by saying, "The Lord hath need of them" (Matt. 21.3). Could it be true that the Lord of creation is in lack and has need? But He himself said it. He knew beforehand that in yonder village an ass with its colt were tied there; He also foreknew that no man had ever sat on that colt. He knew what question the owner of the ass would ask when His disciples loosed them. He knew as well the owner would let them take the ass and the colt if they answered in a certain way. All this is indeed miraculous. Our Lord would rather perform His miracle in this way than create an ass miraculously without either using their ass or sending His disciples on the errand. This is His condescension. He could with one word create an ass colt a hundred times better than any colt then existing in the world, yet He delights in receiving human help.

"And they shall see the Son of man coming on the clouds of heaven with power and great glory" (Matt. 24.30).

After His first coming, the Lord manifested both great authority and glory. At His second coming, He will manifest power and glory. At His first coming, people marveled at his teaching and authority (Matt. 7.28). The Pharisees questioned Him as to the source of His authority (21.23). A centurion believed in His authority (8.8-9). But at His second coming, He will not only manifest authority but also power. He will not ride on a colt (as the Prince of Peace) but will ride instead on a white horse. Power is used in executing the judgment of God. Even when He overturned tables and drove out sheep and oxen with a scourge of cords, He did not use the whip on men. Only at His second coming will He exercise such power.

"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, even upon a colt the foal of an ass" (Zech. 9.9 and quoted in Matt. 21.5).

"Tell ye the daughter of Sion, Behold, thy King cometh unto thee, meek, and sitting upon an ass, and a colt the foal of an ass" (Matt. 21.5).

Matt. 21.2 The other synoptic Gospels mention only the colt, but Matthew reports an ass and a colt. There is a typological reason involved.

v.3 "The Lord hath need of them"—In His capacity as the Creator, the Lord lays claim to them since the entire creation belongs to Him. Commentators usually take the ass to be representative of the Gentiles and the colt, the Jews. Actually the reverse is the truth: the ass represents the Jews and the colt, the Gentiles. Now from Mark’s account (11.7) we see that the Lord rode upon the colt, with the ass no doubt following, thus signifying that the Lord has His hand upon the Gentiles and that the Jews are following. It is most difficult to ride a colt; even an ass expert is not able to do it. Spiritually speaking, before anyone is saved he is truly like a colt. But when he is saved the Lord can ride on such a colt. The horse speaks of war, while the ass speaks of peace. In the instance now before us, the Lord comes as the Prince of Peace riding a colt—that is to say, a young ass ("a colt the foal of an ass"—Matt. 21.5); at His second coming, though, He will ride on a militant white horse.

v.4 This is a fulfillment of a prophecy by the prophet Zechariah (see Zech. 9.9).