Charles Ellicott Commentary Luke 17:10

"Even so ye also, when ye shall have done all the things that are commanded you, say, We are unprofitable servants; we have done that which it was our duty to do." — Luke 17:10 (ASV)

Say, We are unprofitable servants. There is something very suggestive in the use of the same word that we encounter in the parable of the Talents (Matthew 25:30). God, we are taught, may recognize and reward the varying use that people make of gifts and opportunities. But all boasting is excluded; and in relation to God, the person who has gained the ten talents must acknowledge that they have nothing that they have not received, and confess that they stand, as it were, on a level with the unprofitable servant.

Any personal claim on the ground of merit falls to the ground before such a declaration, and even more so, any speculative theory of works of supererogation, and of the transfer of the merits gained by them from one person to their fellow servants and fellow sinners.