Luke 15:15

To feed swine - The basest and vilest of all employments; and, to a Jew, peculiarly degrading. Shame, contempt, and distress are wedded to sin, and can never be divorced. No character could be meaner in the sight of a Jew than that of a swineherd: and Herodotus informs us, that in Egypt they were not permitted to mingle with civil society, nor to appear in the worship of the gods, nor would the very dregs of the people have any matrimonial connections with them. Herod. lib. ii. cap. 47.

Joined himself - Entered the service of that citizen. Hired himself out to him. It would seem that he engaged to do any kind of work, even of the lowest kind.

A citizen - One of the inhabitants of one of the cities or towns of that region, probably a man of property.

Into the fields - Out of the city where the owner lived.

To feed swine - This was a very low employment, and particularly so to a "Jew." It was forbidden to the Jews to eat swine, and of course it was unlawful to keep them. To be compelled, therefore, to engage in such an employment was the deepest conceivable degradation. The "object" of this image, as used by the Saviour in the parable, is to show the loathsome employments and the deep degradation to which sin leads people, and no circumstance could possibly illustrate it in a more striking manner than he has done here. Sin and its results everywhere have the same relation to that which is noble and great, which the feeding of swine had, in the estimation of a Jew, to an honorable and dignified employment.

15:15 And he joined himself to a citizen of that country - Either the devil or one of his children, the genuine citizens of that country which is far from God. He sent him to feed swine - He employed him in the base drudgery of sin.