Jesus used a proverb to summarize His mission (cf. ch15). He used the word "righteous" in a relative sense and perhaps a bit sarcastically since no one is truly righteous, though the Pharisees considered themselves righteous. A person must acknowledge his or her need for Jesus and His righteousness before that one will benefit from the Great Physician"s powers. This acknowledgment of need is what Jesus meant by repentance. Repentance leads to joy in Luke as well as to life (cf. Luke 15:7; Luke 15:10; Luke 15:22-27; Luke 15:32). Luke stressed the positive call of sinners to repentance in this Gospel and in Acts. Luke referred to repentance more than Matthew or Mark did (cf. Luke 3:3; Luke 3:8; Luke 10:13; Luke 11:32; Luke 13:3; Luke 13:5; Luke 15:7; Luke 15:10; Luke 16:30; Luke 17:3-4; Luke 24:47). [source][source][source]
"The connection between Luke 5:32 and Luke 19:10 suggests that they form an inclusion. That Isaiah , we have similar general statements about Jesus" mission early and late in his ministry, statements which serve to interpret the whole ministry which lies between them." [1][source]