Matthew 24:23 - Clarke's commentary and critical notes on the Bible

Then if any man shall say unto you, Lo, here is Christ, or there; believe it not. Then if any man shall say unto you, Lo here is Christ - Our Lord had cautioned his disciples against false Christs and prophets before, Matthew 24:11; but he seems here to intimate that there would be especial need to attend to this caution about the time of the siege. And in fact many such impostors did arise about that time, promising deliverance from God; and the lower the Jews were reduced, the more disposed they were to listen to such deceivers. Like a man drowning, they were willing to catch even at a straw, while there was any prospect of being saved. But as it was to little purpose for a man to take upon him the character of the Christ, without miracles to avouch his Divine mission, so it was the common artifice of these impostors to show signs and wonders, σημεια και τερατα; the very words used by Christ in this prophecy, and by Josephus in his history: Ant. b. xx. c. 7. Among these Simon Magus, and Dositheus, mentioned before; and Barcocab, who, St. Jerome says, pretended to vomit flames. And it is certain these and some others were so dexterous in imitating miraculous works that they deceived many; and such were their works, that if the elect, the chosen persons, the Christians, had not had the fullest evidence of the truth of Christ's mission and miracles, they must have been deceived too: but, having had these proofs, they could not possibly be deceived by these impostors. This is simply the meaning of this place; and it is truly astonishing that it should be brought as a proof for the doctrine (whether true or false is at present out of the question) of the necessary and eternal perseverance of the saints! How abundant the Jews were in magic, divination, sorcery, incantation, etc., see proved by Dr. Lightfoot on this place.