Ambrose of Milan
Catena Aurea · Lukasevangelium 21
And as some spake of the temple, how it was adorned with goodly stones and gifts, he said, As for these things which ye behold, the days will come, in the which there shall not be left one stone upon another, that shall not be thrown down. And they asked him, saying, Master, but when shall these things be? and what sign will there be when these things shall come to pass? And he said, Take heed that ye be not deceived: for many shall come in my name, saying, I am Christ; and the time draweth near: go ye not therefore after them.
Matthew adds a third question, that both the time of the destruction of the temple, and the sign of His coming, and the end of the world, might be inquired into by the disciples. But our Lord being asked when the destruction of the temple should be, and what the sign of His coming, instructs them as to the signs, but does not mind to inform them as to the time. It follows, Take heed that ye be not deceived.