Charles Ellicott Commentary Matthew 23:11

"But he that is greatest among you shall be your servant." — Matthew 23:11 (ASV)

He that is greatest among you —Literally, the greater of you. The words have a two-fold meaning. They either:

1. Assert a law of retribution, as in Mark 9:35: the man who seeks to be greatest will be the servant of all.
2. Point to the other law, of which our Lord’s own life is the highest illustration: that he who is truly greatest will show his greatness not by asserting it, but in a life of ministration.

The second interpretation seems to provide the best meaning overall.