What does Luke 19:9 mean?
This is a beautiful restoration. Jesus is in the home of the Jewish tax collector, Zacchaeus. Zacchaeus chose money over God-worship; he chose the Romans over his own people (Luke 19:1–4). A short time with Jesus, however, has brought him back (Luke 19:5–7). He has repented of his sin and promises to give back the money he has taken unjustly, including the most severe fee included under the Mosaic law (Luke 19:8–9; Exodus 22:1).Jesus has restored him as a son of Abraham (Romans 2:28–29). God made a covenant with Abraham to make him a great nation and bless the nations of the world (Genesis 12:1–3). To be identified with Abraham is to be a true Jew. But some Jews had betrayed that identity.
When John the Baptist saw the Pharisees and Sadducees coming to be baptized, he cried out, "And do not presume to say to yourselves, 'We have Abraham as our father,' for I tell you, God is able from these stones to raise up children for Abraham. Even now the axe is laid to the root of the trees. Every tree therefore that does not bear good fruit is cut down and thrown into the fire" (Matthew 3:9–10). Descendancy from Abraham doesn't make someone a true child of Abraham.
Later, Paul will deal with legalistic Jewish Christians who want Gentile Christians to follow the Jewish law as well, particularly circumcision. Paul points out that God gave Abraham His covenant before Abraham was circumcised. It isn't circumcision that makes someone a child of Abraham (Galatians 3:7–9).
Zacchaeus learns that to be a child of Abraham means to follow his example. "Abraham, 'believed God, and it was counted to him as righteousness'" (Galatians 3:6). As John the Baptist said, it is those who "bear fruit in keeping with repentance" (Matthew 3:8). Zacchaeus fits that description.
Jesus publicly affirms Zacchaeus' position before God, as He often does when restoring someone (Luke 8:44–48; 13:10–16; 18:40–42). The crowd may grumble that Zacchaeus doesn't deserve such grace (Luke 19:7), but "the Son of Man came to seek and to save the lost" (Luke 19:10).