Luke 15:29 - Ellicott's Commentary On The Whole Bible

Lo, these many years do I serve thee. — The very word “I serve,” as a slave serves, is eminently suggestive. The obedience had all along been servile, prompted by fear and hope, even as the slave’s obedience is. The language put into the mouth of the elder son is clearly meant to represent the habitual thoughts of the Pharisees. They are taken, as it were, after our Lord’s manner, as seen in the previous parables, at their own valuation of themselves. They are conscious of no transgressions; but in that very unconsciousness lies the secret of the absence of any sense of joy in being forgiven, of any power to sympathise with the joy of others, even of any satisfaction in the service in which they pride themselves. (Comp. Notes on Luke 7:47-50.) They are scandalised at the gladness which others feel when a penitent returns to God. It seems like an insult and wrong to themselves. Their life has been one of uniform obedience; they have performed their religious duties. Why is so much stir made about those who have fallen as they never fell?