Origen

And note here that the servants do not come to the Lord to be judged, but the Lord shall come to them when the time shall be accomplished. After a long time, that is, when He has sent forth such as are fitted to bring about the salvation of souls, and perhaps for this reason it is not easy to find one who is quite fit to pass forthwith out of this life, as is manifest from this, that even the Apostles lived to old age; for example, it was said to Peter, When thou shalt be old, thou shall stretch forth thy hand; (John 21:18.) and Paul says to Philemon, Now as Paul the aged.