Augustine of Hippo — as excerpted in the Catena Aurea on Mark 13:28-31

“(Epist. 119, 11) All that is said by the three Evangelists concerning the Advent of our Lord, if diligently compared together and examined, will perchance be found to belong to His daily coming in His body, that is, the Church, except those places where that last coming is so promised, as if it were approaching; for instance in the last part of the discourse according to Matthew, the coming itself is clearly expressed, where it is said, When the Son of Man shall come in his glory. (Matt. 25:31) For what does he refer to in the words, when ye shall see these things come to pass, but those things which He has mentioned above, amongst which it is said, And then ye shall see the Son of Man coming in the clouds. The end therefore shall not be then, but then it shall be near at hand. Or are we to say, that not all those things which are mentioned above are to be taken in, but only some of them, that is, leaving out these words, Then shall ye see the Son of man coming; for that shall be the end itself, and not its approach only. But Matthew has declared that it is to be received without exception, saying, When ye shall see all these things, know that it is near, even at the doors. That which is said above must therefore be taken thus; And he shall send his angels, and gather together the elect from the four winds; that is, He shall collect His elect from the four winds of heaven, which He does in the whole of the last hour, coming in His members as in clouds.”