Luke 17:7
But which of you, having a servant plowing or feeding cattle, will say unto him by and by, when he is come from the field, Go and sit down to meat? But which of you, having a servant plowing or feeding cattle, will say unto him by and by, when he is come from the field, Go and sit down to meat?
The verse pictures a master whose servant comes in from plowing or tending cattle in the field and is not told to go at once and sit down to eat. Instead of being invited to rest and eat, the servant is required to prepare the master's supper and serve him first before eating himself. No special thanks is given for work that was only commanded duty.
When believers have done all things commanded them, they have only done their duty and remain unprofitable servants with no claim to merit or special worth. Doing what is commanded is a servant's duty, not grounds for boasting or claiming special worth. The lesson requires humble service and rebukes proud boasting and demeriting others. It condemns the spirit that treats one's own work as of great value while looking on the work of fellow laborers as inferior, exaggerating the value of one's own work and disparaging their service as if one could judge and understand the worth of service.