From: Luke 19:1-10
The Conversion of Zacchaeus
 He (Jesus) entered Jericho and was passing through.  And there was a rich man named Zacchaeus; he was a chief tax collector, and rich.  And he sought to see who Jesus was, but could not, on account of the crowd, because he was small of stature.  So he ran on ahead and climbed up into a sycamore tree to see Him, for He was to pass that way.  And when Jesus came to the place, He looked up and said to him, "Zacchaeus, make haste and come down; for I must stay at your house today."  So he made haste and came down, and received Him joyfully.  And when they saw it they all murmured, "He has gone in to be the guest of a man who is a sinner."  And Zacchaeus stood and said to the Lord, "Behold, Lord, the half of my goods I give to the poor; and if I have defrauded any one of anything, I restore it fourfold."  And Jesus said to him, "Today salvation has come to this house, since he also is a son of Abraham.  For the Son of Man came to seek and save the lost."
1-10. Jesus Christ is the Savior of mankind; He has healed many sick people, has raised the dead to life and, particularly, has brought forgiveness of sin and the gift of grace to those who approach Him in faith. As in the case of the sinful woman (cf. Luke 7:36-50), here He brings salvation to Zacchaeus, for the mission of the Son of Man is to save that which was lost.
Zacchaeus was a tax collector and, as such, was hated by the people, because the tax collectors were collaborators of the Roman authorities and were often guilty of abuses. The Gospel implies that this man also had things to seek forgiveness for (cf. verses 7-10). Certainly he was very keen to see Jesus (no doubt moved by grace) and he did everything he could to do so. Jesus rewards his efforts by staying as a guest in his house. Moved by our Lord's presence Zacchaeus begins to lead a new life.
The crowd begin to grumble against Jesus for showing affection to a man they consider to be an evildoer. Our Lord makes no excuses for his behavior: He explains that this is exactly why He has come--to seek out sinners. He is putting into practice the parable of the lost sheep (cf. Luke 15:4-7), which was already prophesied in Ezekiel: "I will seek the lost, and I will bring back the strayed, and I will bind up the crippled, and I will strengthen the weak" (34:16).
4. Zacchaeus wants to see Jesus, and to do so he has to go out and mix with the crowd. Like the blind man of Jericho he has to shed any kind of human respect. In our own search for God we should not let false shame or fear of ridicule prevent us from using the resources available to us to meet our Lord. "Convince yourself that there is no such thing as ridicule for whoever is doing what is best" ([St] J. Escriva, "The Way", 392).
5-6. This is a very good example of the way God acts to save men. Jesus calls Zacchaeus personally, using his name, suggesting he invite Him home. The Gospel states that Zacchaeus does so promptly and joyfully. This is how we should respond when God calls us by means of grace.
8. Responding immediately to grace, Zacchaeus makes it known that he will restore fourfold anything he obtained unjustly--thereby going beyond what is laid down in the Law of Moses (cf. Exodus 21:37f). And in generous compensation he gives half his wealth to the poor. "Let the rich learn", St. Ambrose comments, "that evil does not consist in having wealth, but in not putting it to good use; for just as riches are an obstacle to evil people, they are also a means of virtue for good people" ("Expositio Evangelii Sec. Lucam, in loc."). Cf. note on Luke 16:9-11).
10. Jesus' ardent desire to seek out a sinner to save him fills us with hope of attaining eternal salvation. "He chooses a chief tax collector: who can despair when such a man obtains grace?" (St. Ambrose, "Expositio Evangelii Sec. Lucam, in loc.").
Source: "The Navarre Bible: Text and Commentaries". Biblical text taken from the Revised Standard Version and New Vulgate. Commentaries made by members of the Faculty of Theology of the University of Navarre, Spain. Published by Four Courts Press, Kill Lane, Blackrock, Co. Dublin, Ireland. Reprinted with permission from Four Courts Press and Scepter Publishers, the U.S. publisher.