Zaccheus is the Greek form of the Jewish name “Zakkai,” which derives from Hebrew zakkay (“righteous one”) (Ezra 2:9; Neh. 7:14)—a ludicrously incongruous name to begin with, given his occupation. He is the very opposite of righteous by any cultural reckoning. For all that, he has been so keen to see Jesus, and so overcome that Jesus greets him and even enters into fellowship with him just as he is, that he spontaneously undertakes a radical redirection of his entire life.
From Luke’s compressed narrative we cannot tell whether his enthusiastic speech to Jesus is more of less immediate, but it seems so: “Look Lord, I give half my goods to the poor; and if I have taken anything from anyone by false accusation, I restore it fourfold” (Luke 19:8). In Judaism, legal restitution for having been guilty of extortion was twenty percent (Lev. 5:16; Num. 5:7), but Zaccheus assumes the harsher penalty imposed on people who stole livestock (Exod. 22:1; Bock 1994-96: 2.1520).
Something truly profound has happened, and in the joy of his acceptance by the Lord he goes much farther than anything the law requires. His exuberant restitution indicates a genuine repentance; as Augustine notes, restitution is not enough for full forgiveness; by giving generously out of his acquired wealthy beyond the normal requirements he takes his action to a higher level (Sermons on the New Testament Lessons 63.3). Augustine here grasps something basic about repentance in the Jewish context. . . .
By committing himself to restoration fourfold and to giving half of his goods to the poor, Zaccheus demonstrated a genuine conversion from his sinful path of life and, in so doing, in a Jewish context, acquired again his full ethical status as a Jew under the law. This is what Jesus, as a rabbi, is formally recognizing when he says, “Today salvation has come to this house, because he also is a son of Abraham” (Luke 19:9). The public promise of restoration to his victims by Zaccheus in the presence of Jesus and the joy of his being accepted by the Lord show that he has now come to terms with the law in the only way that ultimately matters—performatively.
How had this so suddenly happened to him, after a life of “walking in the way of sinners”? The answers surely is the call and acceptance (reconciliation) offered him by Jesus. He has been bowled over by love, a love that will not let him go without a mimetic response. His story is thus a paradigm, for Luke an example of the lost soul found and rescued from inevitably dire consequences. And that is the point of it, Jesus seems to say: “For the Son of Man has come to seek and to save that which was lost” (19:10).