Matthew 8:9

Matthew 8:9. For I also am a man under authority. ‘Also' as in Luke 7:8. The meaning is: I am in service, knowing how to obey and also how to command: having soldiers under myself; hence if I who am after all a subordinate can command, much more one who is ‘in authority' over disease. The last thought is required by the commendation bestowed on his faith.

And I say, etc. I am in the habit of commanding with a word, and am obeyed. The first two commands are represented as addressed to soldiers; the last to the household servant, who works without his personal superintendence. Explicit command, implicit obedience. ‘What gives such charm to the illustration is, that the centurion ever again recurs to his poor faithful servant. Some familiar servant of the Lord Jesus, he thinks, would suffice to restore his poor slave.' (Lange.) He may have thought of spirits doing the work of healing. The servant seems to have been his only one.