Augustine of Hippo
Catena Aurea · Markusevangelium 13
But of that day and that hour knoweth no man, no, not the angels which are in heaven, neither the Son, but the Father. Take ye heed, watch and pray: for ye know not when the time is. For the Son of man is as a man taking a far journey, who left his house, and gave authority to his servants, and to every man his work, and commanded the porter to watch. Watch ye therefore: for ye know not when the master of the house cometh, at even, or at midnight, or at the cockcrowing, or in the morning: Lest coming suddenly he find you sleeping. And what I say unto you I say unto all, Watch.
(Epist. 199, 3) For He not only speaks to those in whose hearing He then spake, but even to all who came after them, before our time, and even to us, and to all after us, even to His last coming. But shall that day find all living, or will any man say that He speaks also to the dead, when He says, Watch, lest when he cometh he find you sleeping? Why then does He say to all, what only belongs to those who shall then be alive, if it be not that it belongs to all, as I have said? For that day comes to each man when his day comes for departing from this life such as he is to be, when judged in that day, and for this reason every Christian ought to watch, lest the Advent of the Lord find him unprepared; but that day shall find him unprepared, whom the last day of his life shall find unprepared.