A.T. Robertson Commentary Matthew 26:10

"But Jesus perceiving it said unto them, Why trouble ye the woman? for she hath wrought a good work upon me." — Matthew 26:10 (ASV)

Why trouble ye the woman? (τ κοπους παρεχετε τη γυναικι?) A phrase not common in Greek writers, though two examples occur in the papyri for giving trouble. Κοπος is from κοπτω, to beat, smite, cut. It is a beating, trouble, and often work, toil. Jesus champions Mary's act with this striking phrase. It is so hard for some people to allow others liberty for their own personalities to express themselves. It is easy to raise small objections to what we do not like and do not understand.

A good work upon me (εργον καλον εις εμε). A beautiful deed upon Jesus himself.