Matthew 9:30 - Ellicott's Commentary On The Whole Bible

Straitly charged them. — The word, implying originally the panting breath of vehement emotion, is one of the strongest used by the New Testament writers (Mark 1:43; Mark 14:5; John 11:33; John 11:38) to express repugnance, displeasure, or the command that implies annoyance. It is as if our Lord saw the garrulous joy on the point of uttering itself, and sought by every means in His power to restrain it. The reasons may be sought, as elsewhere, either (1) in its being good for the spiritual life of the men themselves that they should show forth their praise of God, not with their lips, but in their lives; or (2) in the shrinking from mere notoriety, from the gaze of crowds drawn together to gaze on signs and wonders, and ready to make the Wonder-Worker a king because He wrought them, which St. Matthew, at a later stage, notes as characteristic of our Lord’s ministry (Matthew 12:16-21).