John Chrysostom — as excerpted in the Catena Aurea on Luke 15:11-16

“(Hom. de Patre et duobus Filiis.) There is also in the above-mentioned parable a rule of distinction with reference to the characters or dispositions of the sinners. The father receives his penitent son, exercising the freedom of his will, so as to know from whence he had fallen; and the shepherd seeks for the sheep that wanders and knows not how to return, and carries it on his shoulders, comparing to an irrational animal the foolish man, who, taken by another’s guile, had wandered like a sheep. This parable is then set forth as follows; But he said, A certain man had two sons. There are some who say of these two sons, that the elder is the angels, but the younger, man, who departed on a long journey, when he fell from heaven and paradise to earth; and they adapt what follows with reference to the fall or condition of Adam. This interpretation seems indeed a lenient one, but I know not if it be true. For the younger son came to repentance of his own accord, remembering the past plenty of his father’s house, but the Lord coming called the race of man to repentance, because he saw that to return of their own accord to whence they had fallen had never been in their thoughts; and the elder son is vexed at the return and safety of his brother, whereas the Lord says, There is joy in heaven over one sinner repenting.”