Jamieson, Fausset and Brown on Luke 10:19

19. Behold, I give you, &c.--not for any renewal of their mission, though probably many of them afterwards became ministers of Christ; but simply as disciples.

serpents and scorpions--the latter more venomous than the former: literally, in the first instance (Mr 16:17, 18; Ac 28:5); but the next words, "and over all the power of the enemy, and nothing shall by any means hurt you," show that the glorious power of faith to "overcome the world" and "quench all the fiery darts of the wicked one," by the communication and maintenance of which to His people He makes them innocuous, is what is meant (1Jo 5:4; Ep 6:16).