Bede the Venerable
Catena Aurea · Lukasevangelium 10
And the seventy returned again with joy, saying, Lord, even the devils are subject unto us through thy name. And he said unto them, I beheld Satan as lightning fall from heaven. Behold, I give unto you power to tread on serpents and scorpions, and over all the power of the enemy: and nothing shall by any means hurt you. Notwithstanding in this rejoice not, that the spirits are subject unto you; but rather rejoice, because your names are written in heaven.
That is, I give you the power of casting out every kind of unclean spirit, from the bodies possessed. And as far as regards themselves, He adds, And nothing shall hurt you. Although it might also be taken literally. For Paul when attacked by a viper suffered no injury. (Acts 28:5.) John having drunk poison is not harmed by ita. But I think there is this difference between serpents who bite with the teeth, and scorpionswho sting with the tail, that the serpents signify men or spirits raging openly, scorpions signify them plotting in secret. Or serpents are those which east the poison of evil persuasion upon virtues just beginning, scorpions which go about to corrupt at last virtues which have been brought to perfection.