Catena Aurea on Matthew 16:26–28: Gregory the Great

Or the connexion may be thus; The Holy Church has a period of persecution, and a period of peace; and our Redeemer accordingly distinguishes between these periods in His commands; in time of persecution the life is to be laid down; but in time of peace, those earthly lusts which might gain too great power over us are to be broken through; whence He says, “What does it profit a man?”