It was right for the crowds to welcome him as king for the actions Jesus undertook as he entered the city were those of a king.
In days gone by it was the king's privilege to requisition animals for his use, particularly those animals upon which no one had yet sat. For this reason he said to his disciples, "Go into the village opposite you, and immediately as you enter it you will find a colt tied, on which no one has ever sat; untie it and bring it" for "the Lord has need of it" (Mark 11:2, 3).
He enters the city in this way to fulfill the prophecy of Zechariah: Rejoice greatly, O daughter of Zion! Shout aloud, O daughters of Jerusalem! Behold, your king comes to you; triumphant and victorious is he, humble and riding on a donkey, on a colt the foal of a donkey" (Zechariah 9:9).
Of the Messiah it was foretold, "The scepter shall not depart from Judah, nor the ruler's staff from between his feet, until he comes to whom it belongs; and to him shall be the obedience of the peoples. Binding his foal to the vine and his doney's colt to the choice vine" (Genesis 49:10-11).
When the people cried out to him, "Blessed is he who comes in the name of the Lord" they welcomed him as the one to whom obedience is owed; their recognized their king (Matthew 21:9).
Saint Luke includes an important detail of the Lord's entrance, namely, that the crowds "set him upon" the colt (Luke 19:35). It is a phrase that hearkens to the enthronement of King Solomon, the son of David. To the priest Zadok King David gave the following command: "Take with you the servants of your lord, and cause Solomon my son to ride on my own mule, and bring him down to Gihon; and let Zadok the priest and Nathan the prophet there anoint him king over Israel" (I Kings 1:33-34).
After Jesus was seated on the colt, "most of the crowd spread their garments on the ground," a clear sign of their recognition of the kingship of Jesus (Matthew 21:8). It is an act foreshadowed in the history of Israel: "Then in haste every man of them took his garment, and put it under him on the bare steps, and they blew the trumpet, and proclaimed, 'Jehu is king'" (II Kings 9:13).
After Jesus entered the city and having gone to the temple, he "looked round at everything," again to fulfill the prophecy: "Then I will encamp at my house as a guard, so that none shall march back and forth; no oppressor shall again overrun them, for now I see with my own eyes" (Mark 11:11; Zechariah 9:9).
He enters the city of Jerusalem, to win his great battle, for "on that day the Lord their God will save them for they are the flock of his people" (Zechariah 9:9).
Surrounded with all of these clear and obvious signs, the crowds rightly recognized Jesus as their king, but they misunderstood his kingship and for this reason they would soon reject him.
When the Jesus comes to us, what will our response be?
He comes to us each day; he has not abandoned his people. In every celebration of the Eucharist he comes to us.
In his recent book, Jesus of Nazareth: Holy Week: From the Entrance Into Jerusalem to the Resurrection, Pope Benedict XVI reminds us:
The Church greets the Lord in the Holy Eucharist as the one who is coming now, the one who has entered into her midst. At the same time, she greets him as the one who continues to come, the one who leads us toward his coming. As pilgrims, we go up to him; as a pilgrim and takes us up with him in his 'ascent' to th Cross and Resurrection, to the definitive Jerusalem that is already growing in the midst of this world in the communion that unites us with his body (11).Let us, too, welcome Jesus as King and give our obedience to him who gave his life for us.