Luke 15:17-19

"He came to his senses" is an idiom that indicates repentance. [Note: Jeremias, The Parables . . ., p. 130. See also Greg Forbes, "Repentance and Conflict in the Parable of the Lost Son (Luke 15:11-32)," Journal of the Evangelical Theological Society 42:2 (June 1999):211-229.] He changed his mind about his attitude and decided to make a change in his behavior. The young man used "heaven" as a euphemism for God (Luke 15:18; Luke 15:21). The Jews frequently did this to avoid using God’s name in vain, and there are many examples of this in Luke. The young man meant that he viewed his actions as sin against his father and against God (cf. Psalms 51:4). The son’s proposal to his father, as well as his planned speech, shows the genuineness of his humility and repentance. He was willing to serve his father as a day laborer since his father had a reputation for paying his servants generously (Luke 15:17).

". . . the boy’s proposal indicates that, while he desires the father’s house, he doesn’t understand the father’s heart." [Note: Gary Inrig, The Parables: Understanding What Jesus Meant, p. 19.]