Theophylact of Ohrid
Catena Aurea · Markusevangelium 13
And as he sat upon the mount of Olives over against the temple, Peter and James and John and Andrew asked him privately, Tell us, when shall these things be? and what shall be the sign when all these things shall be fulfilled? And Jesus answering them began to say, Take heed lest any man deceive you: For many shall come in my name, saying, I am Christ; and shall deceive many. And when ye shall hear of wars and rumours of wars, be ye not troubled: for such things must needs be; but the end shall not be yet. For nation shall rise against nation, and kingdom against kingdom: and there shall be earth-quakes in divers places, and there shall be famines and troubles: these are the beginnings of sorrows.
But before answering their question, He strengthens their minds that they may not be deceived, wherefore there follows: And Jesus answering them began to say, Take heed lest any man deceive you? And this He says, because when the sufferings of the Jews began, some arose professing to be teachers, wherefore there follows: For many shall come in my name, saying, I am Christ; and shall deceive many.