Matthew 20:27 - Ellicott's Commentary On The Whole Bible

Whosoever will be chief. — Better, first, as continuing the thought of Matthew 20:16. The “servant” (better, slave) implies a lower and more menial service than that of the “minister” of the preceding verse, just as the “chief” or “first” involves a higher position than the “greatness” there spoken of. We introduce a false antithesis if we assign the “service” to this life, and the “greatness” as its reward to the life after death. The true teaching of the words is that the greatness is the service.