Ambrose of Milan — as excerpted in the Catena Aurea on Luke 21:5-8

“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.”