Zacchaeus was a greedy man. Abandoning all sense of being a true Jew, he worked for those who were oppressing the Jews, the Romans, as a tax-collector in order to get rich quick.
Yet, when Jesus came to his home town Jericho, of all the people he could choose to stay with, he stayed with Zacchaeus. The people of Jericho were outraged. Why was Jesus staying with Zacchaeus?