But, Zacchaeus is also rich, and as Sharon Ringe reminds us in her Commentary on Luke, rich people don't fare as well; e.g., 12:13-21; 16:19-31; 18:18-25.
The people who were there did not approve of Jesus' willing association with someone they perceived to be a sinner.
Zacchaseus' response was to vow to give up half his possessions and repay four-fold anyone he had cheated.
Then Jesus declares, "Today salvation has come to his house because he too is a son of Abraham." As a son of Abraham, he is not clutching his wealth to himself but sharing it with the poor who need it and returning what he did not deserve. Sharon Ringe asserts:
Because of his political and economic role as a chief tax collector, Zacchaeus has never been in a position to consider membership in the people of God something on which he can presume (note John the Baptist's warning in 3:8). In fact, some would say that his profession has made him the equivalent of a Gentile.
Suddenly his membership in the chosen people is reinstated. His earnest promise is not mentioned as a reason, but one is left with the sense that they are connected. His embrace of the opportunity to give alms ... does not earn his new identity.... But the lifestyle he has embraced makes his identity evident.
"Salvation has come to his house," Jesus said. The question of salvation is not how we get it but what we do with it.