Gregory the Great

Ver. 22. But his flesh while he liveth shall have pain, and His soul shall mourn over himself.

Concerning the married Paul saith, Nevertheless, such shall have trouble in the flesh. But they may 'have trouble in the flesh here,' who are even now leading spiritual lives. Wherefore then is it said as it were in a special sense, that there is 'trouble of the flesh' to married persons, seeing that it is not far removed even from the life of the spiritual; excepting that those commonly meet with worse troubles from the flesh, who delight themselves with the pleasures of the flesh? And it is well said, And his soul within him shall mourn over himself; in that whosoever desires to rejoice in himself, by this alone is henceforth in woe, viz. that he has gone far from the true joy. For the true joy of the soul is the Creator. Therefore it is meet that man should ever find in himself sorrow, who, forsaking His Creator, sought joy in himself.